Tox-ini-fmt

- Extend support for additional keys, support tox v4 aliases, and move pass_env/set_env just before commands.
- Use hatchling instead of setuptools.

- Support processing multiple `tox.ini` files at once ([119](https://github.com/tox-dev/tox-ini-fmt/pull/119))
- Fix `tox.ini` formatting when `envlist` ends with a comma ([41](https://github.com/tox-dev/tox-ini-fmt/issues/41))

- Drop Python 3.6 support.

- Disable config parser interpolation

- Diffs are now colored.

- Substitutions for multi-line values go now to the beginning of the configuration (to allow overwriting inherited
values), and in case of multiple such the order is kept ([22](https://github.com/tox-dev/tox-ini-fmt/issues/22))
- Fixed substitutions not being supported within `deps` and `setenv`
([22](https://github.com/tox-dev/tox-ini-fmt/issues/22))
- Support `-r` and conditional markers within `deps` ([21](https://github.com/tox-dev/tox-ini-fmt/issues/21))