Mtf2json

Fixed license in the PyPi package.

- If a critical slot line contains `:size:` or `:SIZE:`, the value is set to the preceding string (the size part is discarded)
- fixes 15
- Updated latest supported commit to `dfeb43e28132c2723ac8e3147e41b00960b989fd`
- `<P>` and `</P>` are now also removed from fluff entries
- Added `--verbose` flag
- Added new testcases
- ShadowHawk SHD-5S
- Hermes_II_HER-4K_Hermes_III
- Code refactoring
- parsing is now done by a generator function
- only known keys are parsed, others are ignored
- lines without keys are ignored, unless it's a known special case
- replaced the `mtf2json.pyi` stub file with `py.typed`
- switched from `flake8` to `ruff` (for linting and formatting)
- reformatted all existing code

Fluff lines without keys are now ignored (fixes https://github.com/juk0de/mtf2json/issues/14).

Fixed regular expression that detects weapon lines (fixes https://github.com/juk0de/mtf2json/issues/12).

* improved error handling
* updated supported MM commit
* conversion rate is now 100% (3954 / 3954) for biped mechs
* [Milestone 1](https://github.com/juk0de/mtf2json/milestone/1) has been reached :tada:

* added `--mm-commit` option that prints the latest supported MegaMek commit ID
* development and testing improvements