Getdents

* Bump minimal Python version to 3.8
* Refactor to use only [Limited API](https://docs.python.org/3/c-api/stable.html#contents-of-limited-api)
* Wheels for CPython are now marked as `abi3` (means, new versions of Python should be able consume existing wheels)
* Added compatibility with [musl libc](https://musl.libc.org/)
* Automated build and publication to PyPI

**Full Changelog**: https://github.com/ZipFile/python-getdents/compare/v0.3.0...v0.4.0

* Minor typing fixes
* Minor getdents_raw memory optimization
* Remove old `pretend` from dev dependencies
* Apply black code style
* Migrate all configs to `pyproject.toml`

**Full Changelog**: https://github.com/ZipFile/python-getdents/compare/v0.3.1...v0.3.2

**Full Changelog**: https://github.com/ZipFile/python-getdents/compare/v0.3...v0.3.1

No changes in `getdents()` and `getdents_raw()` API, minor housekeeping.

New feature: CLI to use in shell scripting.

**Full Changelog**: https://github.com/ZipFile/python-getdents/compare/v0.2...v0.3

**Full Changelog**: https://github.com/ZipFile/python-getdents/compare/v0.1...v0.2