* Change name of `MATCH_CLASS` to `MATCH_POSITIONAL`.
* Drop `__attributes__` and use `__match_args__` instead.
* For `MATCH_DEFAULT`, `__match_args__` acts a map from positions to names.
* For `MATCH_POSITIONAL`, `__match_args__` acts a map from names to positions.
* Change semantics of `MATCH_DEFAULT` when match class patterns to those of PEP 634.
* Update translations.
* Further expand examples