Merge pull request 'update-mds' (#2) from update-mds into main

Reviewed-on: #2

docs/cli-reference.md

@@ -1 +1,117 @@
 # CLI Reference
+
+All commands support `-h` / `--help`.
+
+---
+
+## `fpy new`
+
+Scaffold a new ForeignThon project.
+
+```bash
+fpy new <name> --lang <code>       # create in new directory
+fpy new --lang <code>              # initialize current directory (must be empty)
+fpy new <name> --lang <code> --no-git
+fpy new <name> --lang custom       # scaffold a blank language pack
+```
+
+| Flag | Description |
+|---|---|
+| `--lang`, `-l` | Language code — required |
+| `--no-git` | Skip `git init` and initial commit |
+
+!!! note "Using `--lang custom`"
+    Prompts for a language code, English name, and native name. Creates a `custom.json` with all Python keywords pre-filled as stubs and wires it up in `.foreignthon.toml` automatically.
+
+---
+
+## `fpy run`
+
+Transpile and run a source file.
+
+```bash
+fpy run script.es.py
+fpy run script.py --lang es        # override language detection
+fpy run script.es.py --keep        # also write the compiled .py to disk
+```
+
+| Flag | Description |
+|---|---|
+| `--lang`, `-l` | Override language detection |
+| `--keep` | Write `.compiled.py` alongside source after running |
+
+---
+
+## `fpy compile`
+
+Transpile to standard Python without running.
+
+```bash
+fpy compile script.es.py                 # → script.compiled.py (same directory)
+fpy compile script.es.py -o dist/        # → dist/script.compiled.py
+fpy compile script.es.py -o output.py    # → output.py
+```
+
+| Flag | Description |
+|---|---|
+| `--output`, `-o` | Output file or directory |
+
+---
+
+## `fpy decompile`
+
+Convert standard Python back to a foreign language. Keywords and builtins are translated — variable names are untouched.
+
+```bash
+fpy decompile script.py --lang es
+fpy decompile script.py --lang es --postfix
+fpy decompile script.py --lang es -o out/
+```
+
+| Flag | Description |
+|---|---|
+| `--lang`, `-l` | Target language — required |
+| `--postfix` | Rewrite conditionals to `@@` postfix style |
+| `--output`, `-o` | Output file or directory |
+
+!!! note
+    Decompile is lossy — variable names and comments are not translated back. It is useful for bootstrapping a foreign-language version of an existing Python file, not as a perfect round-trip.
+
+---
+
+## `fpy check`
+
+Validate syntax without running.
+
+```bash
+fpy check script.es.py
+# ✓ script.es.py looks good.
+# or
+# ✗ Syntax error: invalid syntax (script.es.py, line 4)
+```
+
+Exits with code `1` on failure — useful in CI pipelines.
+
+---
+
+## `fpy pack`
+
+Validate a language pack JSON file against the required schema.
+
+```bash
+fpy pack mylang.json
+# ✓ Pack 'Russian' is valid.
+# or
+# ✗ Missing sections: {'error_messages'}
+```
+
+---
+
+## Language detection order
+
+When running a file, ForeignThon resolves the language in this order:
+
+1. `--lang` flag (highest priority)
+2. Shebang comment: `# foreignthon: es`
+3. File extension: `.es.py` → `es`
+4. `.foreignthon.toml` in the project root

docs/custom-packs.md

@@ -1 +1,95 @@
-# Custom Packs
+## Custom Packs
+
+ForeignThon lets you extend or override any installed language pack locally — no PyPI account, no new package required. You can also scaffold a completely new language from scratch.
+
+---
+
+## Local override
+
+Create a `custom.json` in your project root with only the keys you want to change:
+
+```json
+{
+  "builtins": {
+    "show": "print"
+  },
+  "keywords": {
+    "when": "if"
+  }
+}
+```
+
+Then reference it in `.foreignthon.toml`:
+
+```toml
+[foreignthon]
+lang = "es"
+custom_pack = "custom.json"
+```
+
+Custom keys are merged on top of the installed pack. Installed pack keys are preserved — only the keys you define in `custom.json` are overridden.
+
+!!! tip
+    ForeignThon walks up the directory tree to find `.foreignthon.toml`, so you can place it at the project root and run `fpy` from any subdirectory.
+
+---
+
+## Scaffold a new language
+
+If no pack exists for your language yet:
+
+```bash
+fpy new myproject --lang custom
+```
+
+You will be prompted for:
+
+- Language code (e.g. `ru`, `fr`, `ar`)
+- English name (e.g. `Russian`)
+- Native name (e.g. `Русский`)
+
+This generates a `custom.json` based on the official template — every Python keyword, builtin, exception, and stdlib module is listed with the English value as a placeholder. Replace the **keys** with your language's words.
+
+```json
+{
+  "keywords": {
+    "if": "if",      ← replace the key, keep the value
+    "for": "for",
+    "def": "def",
+    ...
+  }
+}
+```
+
+The `.foreignthon.toml` is automatically wired to use this file.
+
+---
+
+## Pack schema
+
+A standalone pack must have these top-level sections:
+
+| Section | Purpose |
+|---|---|
+| `meta` | Name, code, version, authors |
+| `keywords` | Python reserved words |
+| `builtins` | Built-in functions |
+| `exceptions` | Built-in exception classes |
+| `error_messages` | Translations for bilingual error output |
+| `stdlib` | Common standard library module names |
+| `postfix_keywords` | English keywords to rewrite in `--postfix` output |
+
+Validate your pack at any time:
+
+```bash
+fpy pack custom.json
+# ✓ Pack 'Russian' is valid.
+```
+
+---
+
+## Publishing
+
+Once your `custom.json` is complete and working, you can turn it into a proper `foreignthon-xx` package on PyPI so others can install it with `pip install foreignthon-xx`.
+
+See [Contributing → Language Packs](contributing/language-packs.md) for the full guide. Custom Packs

docs/getting-started.md

@@ -1 +1,135 @@
 # Getting Started
+
+## Requirements
+
+- Python 3.9 or later
+- A language pack (`pip install foreignthon-xx`)
+
+---
+
+## Installation
+
+```bash
+pip install foreignthon
+```
+
+For global CLI access across projects, use `pipx`:
+
+```bash
+pipx install foreignthon
+```
+
+---
+
+## Create a project
+
+```bash
+fpy new myproject --lang <code>
+cd myproject
+```
+
+This scaffolds:
+
+```
+myproject/
+├── .foreignthon.toml   # project config
+├── .gitignore
+├── README.md
+└── src/
+    └── main.<lang>.py  # hello world in your language
+```
+
+The `.foreignthon.toml` stores your language and any local pack overrides:
+
+```toml
+[foreignthon]
+lang = "es"
+# custom_pack = "custom.json"
+```
+
+---
+
+## File naming
+
+ForeignThon detects the language from the file extension:
+
+```
+script.es.py   →  Spanish
+script.ta.py   →  Tamil
+script.fr.py   →  French
+```
+
+You can also declare the language at the top of the file:
+
+```python
+# foreignthon: es
+```
+
+Or override it at runtime:
+
+```bash
+fpy run script.py --lang es
+```
+
+---
+
+## Run
+
+```bash
+fpy run src/main.es.py
+```
+
+---
+
+## Compile
+
+```bash
+fpy compile src/main.es.py
+# → src/main.compiled.py
+```
+
+```bash
+fpy compile src/main.es.py -o dist/
+# → dist/main.compiled.py
+```
+
+The compiled file is standard Python. Commit it alongside your source — anyone can run it without ForeignThon installed.
+
+---
+
+## Validate
+
+```bash
+fpy check src/main.es.py
+# ✓ main.es.py looks good.
+```
+
+Checks syntax without running — useful in CI.
+
+---
+
+## Errors
+
+When something goes wrong, ForeignThon shows the error in your language first, then English:
+
+```
+[ES] ErrorDeDivisionCero: Error división por cero
+[EN] ZeroDivisionError: division by zero
+     File "src/main.es.py", line 8
+```
+
+Tracebacks point to your original source file, not any intermediate.
+
+---
+
+## Variable names
+
+Variable names are completely optional — English names work alongside foreign keywords with no issues. Only keywords and builtins are ever swapped.
+
+---
+
+## Next steps
+
+- [CLI Reference](cli-reference.md) — all commands and flags
+- [Language Packs](language-packs/index.md) — available languages
+- [Custom Packs](custom-packs.md) — extend or override a pack locally

docs/index.md

@@ -1 +1,42 @@
 # ForeignThon
+
+Write Python in any human language.
+
+ForeignThon is a transpiler that converts `.xx.py` files into standard Python — keywords, builtins, and exceptions all translated into your language. The compiled output runs anywhere without ForeignThon installed.
+
+---
+
+## How it works
+
+```
+source.es.py  →  fpy  →  source.compiled.py  →  Python
+```
+
+ForeignThon uses Python's `tokenize` module to swap `NAME` tokens. Strings, comments, and f-strings are never touched. The result is identical, valid Python.
+
+---
+
+## Install
+
+```bash
+pip install foreignthon
+pip install foreignthon-es   # or any other language pack
+```
+
+---
+
+## At a glance
+
+| Feature | Description |
+|---|---|
+| Transpiler | Tokenizer-based, safe, unicode-aware |
+| File format | `.xx.py` where `xx` is the language code |
+| Errors | Shown in your language first, English below |
+| Postfix syntax | `@@` operator for SOV languages |
+| Custom packs | Local JSON override, no PyPI needed |
+| CLI | `fpy run`, `fpy compile`, `fpy decompile`, `fpy new` |
+
+---
+
+[Get started →](getting-started.md){ .md-button .md-button--primary }
+[CLI Reference →](cli-reference.md){ .md-button }

docs/language-packs/index.md

@@ -1 +1,55 @@
 # Language Packs
+
+Language packs are separate PyPI packages that define keyword, builtin, and exception mappings for a specific human language. Each is installed independently and discovered automatically by ForeignThon.
+
+---
+
+## Install a pack
+
+```bash
+pip install foreignthon-<code>
+```
+
+Multiple packs can coexist — install as many as you need.
+
+---
+
+## Available packs
+
+| Language | Code | Install |
+|---|---|---|
+| Spanish | `es` | `pip install foreignthon-es` |
+| Tamil | `ta` | `pip install foreignthon-ta` |
+
+---
+
+## How discovery works
+
+ForeignThon uses Python [entry points](https://packaging.python.org/en/latest/specifications/entry-points/) to discover installed packs. Installing a pack is sufficient — no configuration required.
+
+```toml
+# Each pack registers itself in its pyproject.toml:
+[project.entry-points."foreignthon.langs"]
+es = "foreignthon_es"
+```
+
+---
+
+## What a pack covers
+
+| Section | Examples |
+|---|---|
+| Keywords | `if`, `for`, `def`, `class`, `return` … |
+| Builtins | `print`, `range`, `len`, `type` … |
+| Exceptions | `ValueError`, `TypeError`, `KeyError` … |
+| Error messages | Bilingual error output translations |
+| Stdlib | `math`, `sys`, `os`, `random` … |
+| Postfix keywords | Which keywords to rewrite with `@@` on decompile |
+
+Third-party library names (numpy, pandas, etc.) are intentionally out of scope.
+
+---
+
+## Don't see your language?
+
+Anyone can publish a `foreignthon-xx` pack — no core access required. See [Contributing → Language Packs](../contributing/language-packs.md) to get started, or use a [local custom pack](../custom-packs.md) in the meantime.

docs/postfix-syntax.md

@@ -1 +1,87 @@
-# Postfix Syntax
+## Postfix Syntax
+
+Some languages are SOV — subject-object-verb — meaning the condition naturally comes before the keyword rather than after it. ForeignThon supports this with the `@@` operator.
+
+---
+
+## The problem
+
+In English-order Python, the keyword always comes first:
+
+```python
+if condition:
+    ...
+```
+
+In many languages, the natural order is the opposite — the condition is stated first, then the action. Forcing English word order on these languages makes the code feel unnatural.
+
+---
+
+## The solution
+
+The `@@` operator lets you put any keyword after its expression:
+
+```
+condition @@keyword:
+    body
+```
+
+This is equivalent to:
+
+```
+keyword condition:
+    body
+```
+
+Both produce identical compiled Python. `@@` is purely a source-level syntax — it is processed before tokenization and never appears in the output.
+
+---
+
+## Rules
+
+- `@@` rewrites only the line it appears on — nothing else changes
+- Indentation follows standard Python rules, unchanged
+- Prefix and postfix can be mixed freely in the same file
+- Works for any keyword in any language pack
+- `@@` is not valid Python syntax, so it never conflicts with existing code
+
+---
+
+## Supported constructs
+
+| Construct | Prefix | Postfix |
+|---|---|---|
+| if | `keyword condition:` | `condition @@keyword:` |
+| elif | `keyword condition:` | `condition @@keyword:` |
+| while | `keyword condition:` | `condition @@keyword:` |
+| def | `keyword name(args):` | `name(args) @@keyword:` |
+| class | `keyword Name:` | `Name @@keyword:` |
+| for | `keyword var in iter:` | `var @@in_kw iter @@for_kw:` |
+
+!!! note
+    `for` loops with postfix require two `@@` operators and can be complex. Most users keep `for` in prefix style.
+
+---
+
+## Decompile with postfix
+
+When converting Python back to a foreign language, pass `--postfix`:
+
+```bash
+fpy decompile script.py --lang <code> --postfix
+```
+
+Which keywords get rewritten is controlled by the `postfix_keywords` list in the language pack JSON. A language that uses SVO order sets this to `[]` — postfix output is never forced on languages that don't need it.
+
+```json
+"postfix_keywords": ["if", "elif", "while", "def", "class"]
+```
+
+---
+
+## Input vs output
+
+| Direction | Mechanism | Controlled by |
+|---|---|---|
+| Input (writing `.xx.py`) | `@@` in source | Always available for any keyword |
+| Output (`fpy decompile --postfix`) | Pack's `postfix_keywords` | Language pack author | Postfix Syntax