README: target information

README.md

@@ -24,6 +24,25 @@ targets:
 - chessNoComputer: The user can play both sides in a GUI. Mainly added for testing the move
   generator.
 - findMagicNumber: finds Magic Numbers for the magic bitboard.
+- moveGenTest: tests the move generator
+
+## Testing
+
+The target moveGenTest with its source in the test directory is a [perft](https://www.chessprogramming.org/Perft).
+It works by counting the number of leaf nodes of the move generation with a
+certain depth. The results where verified with [stockfish](https://stockfishchess.org/).
+
+## Implementation
+
+The engine is implemented using [bitboards](https://www.chessprogramming.org/Bitboards)
+to store the position. A bitboard is an array of 64-Bit unsigned integers. The bitboard contains one
+element per piece and square. Each Bit of the integer corresponds to one field
+on the board, whether the piece stands there (1) or not (0). This allows use to
+use bitwise operations to calculate information we need, really fast.
+
+The move generation of pseudo-legal moves (moves without considering whether the
+king is in check) is mostly straightforward. We pre-generate some data in
+`src/generateCode/moveConsts.c`, so that we can calculate the moves faster.
 
 # sources