Chinese chess game

$ ./chess -h
Usage of ./chess:
  -color string
    	decide self color(defaults to red). (default "red")

For example,

• ./chess --color red (equivalent to ./chess)
• ./chess --color black

• Undo button: take back a move with no limit on the number of moves
• Redo button: Revoke a take-back with no limit on the number of moves
• RunAI button: Start the AI to get its best move recommendation
• StopAI button: Stop AI
• Text input (rightmost side): The number of moves the AI will explore, defaults to 10.

• Minimax
• Alpha-beta pruning

Any contribution is welcome!

• Most importantly, We need to enhance the speed and accuracy of the AI.
• It's only tested on MacBook (darwin/arm64), so it'd be great to test it on other platforms.