added rook, created bishop file

Board.java

@@ -6,10 +6,10 @@ public class Board {
   public Board() {
     board = new Piece[8][8];
     for (int i = 0; i <= 7; i++) {
-      board[i][2] = new Pawn(i + 1, 2, "Black");
+      board[i][1] = new Pawn(i, 1, "Black");
     }
     for (int i = 0; i <= 7; i++) {
-      board[i][7] = new Pawn(i + 1, 7, "White");
+      board[i][6] = new Pawn(i, 6, "White");
     }
   }