- rename games.user_name to games.user_cd
- rename go_players.black_name to go_players.black_cd
- rename go_players.white_name to go_players.white_cd
- rename rengo_players.black1_name to rengo_players.black1_cd
- rename rengo_players.black2_name to rengo_players.black2_cd
- rename rengo_players.white1_name to rengo_players.white1_cd
- rename rengo_players.white2_name to rengo_players.white2_cd
tidy code