MineChess - Шахматы в Майнкрафт

-Added Insufficient Material rule.

• Now the game will end if the remaining pieces on the board make it impossible for either player to deliver a checkmate. This is considered a tie. This occurs in specific cases such as king versus king, king and bishop versus king, king and knight versus king, or both sides having only a bishop on the same color.

• This includes new end_game action and reward action for this case.