Maybe add contributing guidelines to readthedocs

[cblegare]

Hello again!

May I suggest you add your nice contributor's guide to the read the docs? This can be done without duplicating the documentation's source:

1. Convert (manually) CONTRIBUTING.md to RestructuredText as CONTRIBUTING.rst (Github will still render it just fine as HTML).

2. Add a contributing.rst file to your doc and add it somewhere to the doctree with the following content:

.. _contributing:

.. include:: ../CONTRIBUTING.rst

3. There is no third step!

[cblegare]

I see you depend on the MyST parser for the docs, so you may not have to convert md -> rst. I also see it is only used to include the README.md in docs/index.md. One could prefer to simply convert README.md to README.rst an remove the MyST parser, Github will manage this just fine.

[OliverHofkens]

Thanks for the great suggestions, that sounds great!
I'm gonna try to reserve some time next friday to look at this and the other suggestions that have come up so far.

[OliverHofkens]

This is now done and live with the newly released v0.4.2: https://odata-query.readthedocs.io/en/latest/contributing.html
One minor note: Pypi refuses packages with unparseable README's, so I had to remove the Sphinx :ref: to the contributing page there.
Thanks for helping us improve this package!