Check action design consistency (Chess, Shogi, AnimalShogi)

[sotetsuk]

Is it easy to recover the square info with same operation?

• Animal Shogi: x, sq = jnp.int8(a // 12), jnp.int8(a % 12)
• Chess: from_, plane = label // 73, label % 73 (consistent to OpenSpiel)
• Shogi: direction, to = jnp.int8(action // 81), jnp.int8(action % 81) (consistent to dlshogi)

Also, write these info to docs.

[sotetsuk]

Seems sq = label % boardsize is natural? (considering Go and Hex)

[sotetsuk]

Fixing the implementation is impossible. So, prepare get_board_position(label), get_plane(label) or something