Better C++ docs

[chaitan94]

Right now we are using doxygen out of the box - which is fine, although, honestly I think it could be better - both in terms of usability and looks. I have two different approaches in mind, which I think are worth considering:

Approach 1. Use MCSS theme

• Pros: Best part, IMO, is the quick search feature as soon as you press tab. It increases usability by a lot.
• https://mcss.mosra.cz/documentation/doxygen/
• Example (magnum): https://doc.magnum.graphics/magnum/

Approach 2. Integrate with sphinx/readthedocs

• sphinx/readthedocs seems to have support for C++ code. Although I have yet to look into how viable an option this is.
• Pros: This would bring both Python and C++ documentation to a single place. This means common concepts could be documented together. However, it is worth evaluating this approach further if coupling them together might complicate some other things.
• https://www.sphinx-doc.org/en/master/usage/restructuredtext/domains.html#cpp-domain

Right now I am leaned a bit towards Approach 1. Any ideas/suggestions/contributions towards this would be greatly appreciated.

[chaitan94]

Went ahead with Approach 1. Has been implemented in https://github.com/adonmo/meos/commit/d17cedfc04f2ef13456fbd352741adf2fc54bada.

The new documentation is live at: https://meos.netlify.app/

Also, a similar change has been contributed to the upstream template on which the base CMake code structure of MEOS was based on: https://github.com/TheLartians/ModernCppStarter/pull/49.