* In this release, the observation values for the _terminated_ state in **Hex** have been changed (in 1288). There is no impact on the agent's learning or performance. In accordance with the versioning policy, the Hex environment version remains unchanged.
* `player_id` argument in `Env.observe`is deprecated
What's Changed
* [Docs] Update hex.md by KazukiOhta in https://github.com/sotetsuk/pgx/pull/1285
* [AlphaZero] Fix minor typo in train.py by KazukiOhta in https://github.com/sotetsuk/pgx/pull/1286
* [Hex] Extract game specific attributes by sotetsuk in https://github.com/sotetsuk/pgx/pull/1287
* [Hex] Extract logic functions by sotetsuk in https://github.com/sotetsuk/pgx/pull/1288
* [Hex] Create `Game` class by sotetsuk in https://github.com/sotetsuk/pgx/pull/1289
* [Hex] Enhance terminal computation by sotetsuk in https://github.com/sotetsuk/pgx/pull/1290
* [Hex] Use `_player_order` by sotetsuk in https://github.com/sotetsuk/pgx/pull/1291
* [API] Deprecate `player_id` in observe by sotetsuk in https://github.com/sotetsuk/pgx/pull/1292
* [Docs] Update README by sotetsuk in https://github.com/sotetsuk/pgx/pull/1293
**Full Changelog**: https://github.com/sotetsuk/pgx/compare/v2.4.2...v2.5.0