Chess game updates

Today, I made some decent functionality changes. It took very long because I couldn’t figure it out for a while because I had to do research on how to, but I figured out how to do the en passant, threefold repetition, and 50 move rule by updating the JS. I also fixed the previous issue where when the player is in check by another, they can’t block it with another piece, even if they should be able to. I was also able to fix this issue as well. Unfortunately, the logic of JS I made for the en passant, threefold repetition and 50 move rule introduced a new problem of erasing any piece that can be taken. For example, if a pawn is able to take another and I click on that pawn to see its possible moves, and then click on another piece, the opposing pawn disappears. I didn’t have enough time to fix the issue and will be working on it another time.