support to Doxygen

[amamory]

not all class definitions have Doxygen comment style. It would be nice to have some tec docs. there are some tutorials about doxygen deployment in github
https://gist.github.com/vidavidorra/548ffbcdae99d752da02.

There also alternatives to doxygen, based on markdown.
I like ReadTheDocs, for instance, https://dont-be-afraid-to-commit.readthedocs.io/en/latest/documentation.html

it would also be nice to have readme.md files in the main dirs/modules to briefly explain its contents.

Choose one format and stick with it !