* chore(deps): drop support for Python 3.7
In link with the recent release of [Manim v0.17.0](https://github.com/ManimCommunity/manim/releases/tag/v0.17.0), Manim Slides drops support for Python 3.7.
* feat(cli): check for newer Manim Slides version
Uses same logic as manim to check for a new version
* fix(lib): reset correct version
* fix(ci): add type stubs for requests
* refactor(lib): rename `main` to `__main__`
This allows to call the module using `python -m manim-slides`, useful for profiling, etc.
* fix(setup): update name
