Introducing Chess No. 25 v0.5

Chess No. 25 v0.5 is checking for rules, if the player is checked and more. Because it can't be played on itch.io for now, play it on Vercel: https://chess-no-25.vercel.app

En passant is still missing, but castling is here and there are themes.

Remember: the themes are created by the community. You can always create your own theme.