-NEW VARIANTS:
-https://www.chessvariants.com/mvopponent.dir/hypnotic-chess.html
-https://www.chessvariants.com/mvopponent.dir/mesmer-chess.html
-https://www.reddit.com/r/TotemChess/comments/imi3v7/totem_rules/
---> replaced by "Joker" chess --> start on bishop of our color (instead),
- moves like a Bishop + Dabbabah, can swap with a piece *on same color* (as a move) at anytime. hmm
- or rather: start as in Antiking + Mesmer, in front of. moves like an amazon. swap with any color. better!
-http://history.chess.free.fr/rollerball.htm
- https://www.chessvariants.com/40.dir/rollerball/index.html
+"FreeBoard", re-using a lot of Board logic, but with SVG (empty) board + SVG (empty) reserves.
+Will be used for variants with custom non-rectangular board (Hex, at least)
+Or, with other board shapes (see greenchess.net for example)