DOCS: Update sphinx configuration, docs, citations

[nawtrey]

Changes

• Adds .readthedocs.yaml

• Converts citation to use BibTex via the sphinxcontrib.bibtex extension. References are now stored in docs/references.bib and can be cited using :footcite:. Citations for each page will show at the bottom by adding .. footbibliography::.

• Adds brief description of BibTex citations to docs/README.md

• Fixes issues with equation formatting in calculations.py and diagrams.py

• Fixes issues with citations in calculations.py and diagrams.py

• Removes "Kinetic Diagram Analysis" from titles of main modules (e.g. calculations.py)

• Adds usage.rst which covers KDA installation and basic usage, including generating state probabilities and plotting diagrams

• Updates index.rst such that some kinetic diagrams are rendered on the home page

• Changes version and release in conf.py to automatically update based on imported kda version

• Fixes #23

• Fixes #93

[nawtrey]

Okay it looks like the docs are finally building. I'm gonna squash & merge this, any other changes to the docs can be handled in much smaller bite sizes.