Feature request: rewrite index.html files in README.md format

[anton-malakhov]

GitHub does not show index.html as directory description and reading index.html files is hard in plain text.
Markdown (.md) syntax is clean for direct reading (and maintaining!) and also converts easily to .html preserving all the formatting features.

E.g. online converter is here: https://pandoc.org/try/?text=&from=html&to=markdown_github

[tbbdev]

It will be hard to support two versions of documentation. We need to think how to make it optimal.

[svenevs]

How is the documentation generated? It looks like doxygen is used (some @ingroup going on), but I couldn't actually find any of the tools in this repo to generate the docs. FWIW, you can just add the markdown files to INPUT with doxygen.

[aleksei-fedotov]

It seems GitHub can render .rst file format as well. oneTBB is moving in this direction. So, this will be automatically covered. Therefore, I think the issue can be closed. Interested people could reopen it if they deem useful.