[DOC]: sphinxcontrib-bibtex preview

[echedey-ls]

• Preview of Standard citation style across docs #2202
• I am familiar with the contributing guidelines
• Tests added
• Updates entries in docs/sphinx/source/reference for API changes.
• Adds description and name entries in the appropriate "what's new" file in docs/sphinx/source/whatsnew for all changes. Includes link to the GitHub Issue with :issue:`num` or this Pull Request with :pull:`num`. Includes contributor name and/or GitHub username (link with :ghuser:`user`).
• New code is fully documented. Includes numpydoc compliant docstrings, examples, and comments where necessary.
• Pull request is nearly complete and ready for detailed review.
• Maintainer: Appropriate GitHub Labels (including remote-data) and Milestone are assigned to the Pull Request and linked Issue.

See #2202 for context.

Let's keep conversation on whether this change is valuable to the repo in #2202, since there are some issues that must be taken into account:

• Current issues of https://github.com/mcmtroffaes/sphinxcontrib-bibtex/
  • That includes the not-so-maintained dependency pybtex (context: https://bitbucket.org/pybtex-devs/pybtex/issues/169/replace-pkg_resources-with via Cannot import due to pkg_resources on Python 3.12 mcmtroffaes/sphinxcontrib-bibtex#345)
• Issues of https://bitbucket.org/pybtex-devs/pybtex/issues?status=new&status=open

TODO list

if we pursue this change:

• Remove reference_format.css and related code
• Select the exact type of reference type we want (ieeetr probably) https://www.overleaf.com/learn/latex/Bibtex_bibliography_styles
• Remove :doi: role (?)

Example

Only affects one function for now, pvlib.shading.shaded_fraction1d:

• Current docpage: https://pvlib-python.readthedocs.io/en/latest/reference/generated/pvlib.shading.shaded_fraction1d.html
• This PR's docpage: https://pvlib-python--2204.org.readthedocs.build/en/2204/reference/generated/pvlib.shading.shaded_fraction1d.html

[echedey-ls]

Closing as discussed :)