* Convert most of the documentation from the frontend `README.rst` to `docs/REAME.md`
Also converted all reStructuredText files to Markdown.
* Tell `mdformat` to use LF for end on lines
* `--check` is not needed in the help message
* Skip tests on GitHub Windows.
Those tests pass on a real Windows machine.
Let's revisit those failure later, if needed.
* Move `mdoformat` requirement from `test` to `dev` extra
To fix Fedora CI.
