Keep track of whether the board is animating (not used for anything yet).
[remoteglot] / www / css /
drwxr-xr-x   ..
-rw-r--r-- 1344 chessboard-0.3.0.css
-rw-r--r-- 833 chessboard-0.3.0.min.css
-rw-r--r-- 2764 remoteglot.css