Add documentation for read-the-docs based on rocm-docs-core

[Maetveis]

Items left to do:

• [ ] remove custom pinning of doxysphinx when https://github.com/boschglobal/doxysphinx/pull/102 is merged will be done later
• [x] get all namespaces to show up in doxygen output
• [x] Move contributing etc, to documentation
• [x] Move supported API to documentation and fix the links

Replaces: #98

[cgmb]

Am I missing something? All I see is:

This is an autogenerated index file. Please create an index.rst or README.rst file with your own content under the root (or /docs) directory in your repository.

EDIT: Ah. There are two "View Docs" buttons on the build page, but only one of them is for the docs associated with the build.

[saadrahim]

LTGM. I can keep filling thing in from here. Thanks for getting this skeleton put together.

It would be nice at some point to figure out how to get intersphinx working together with breathe. For a project like hipfort that refers frequently to functions in other projects, that support for referencing other project docs would be useful.

Intersphinx is happening very soon. https://github.com/RadeonOpenCompute/ROCm/issues/2015