Awesome-pattern-matching

Fixes 2

Released as https://pypi.org/project/awesome-pattern-matching/0.21.2/

- track python 3.10 development, compatible with alpha7

- Added an `.explain()` which can help with understanding why a match did not succeed

- `MatchContext.match` matches collection patterns if type matches exactly
- Add support for using `range` as a pattern
- 100% test (line and branch) coverage

- Added `typefoo` module (`Parameters`, `KwArgs`, `VarArgs`, see [tests](https://github.com/scravy/awesome-pattern-matching/blob/main/tests/test_typefoo.py))
- Added `Attrs`
- Except for newly added `typefoo` module, everything has 100% branch and line coverage

- Added `captureall` argument to `match`
- Improved nesting `Capture` patterns