Sphinx workflow

[engrosamaali91]

In order to setup a GitHub Workflow we require gh-pages in fastsurfer repository where html pages will be deployed.

[dkuegler]

Importantly, move not copy.

[dkuegler]

1. rebase on upstream
2. Docker and Singularity Files:
   1. Remove the files in doc/overview
   2. Update the Links in other Markdown files
3. Examples etc.
   1. rename FASTSURFER_EXAMPLES.md to EXAMPLES.md (and other FASTSURFER_* files)
   2. update the links to examples etc. in all Markdown files (examples moved from README.md to doc/overview/FASTSURFER_EXAMPLES.md)

[dkuegler]

As stated in PR.

[dkuegler]

We are finally at a stage where the build works and the error is because of something completely different. In this case, the download_checkpoints.py script is broken, because it was not updated by #467 .

[m-reuter]

What still needs to be done here:

• Import of download_checkpoints fails as it gets ImportError: cannot import name 'VINN_AXI' from 'FastSurferCNN.utils.checkpoint' and other similar things. This needs to be fixed in dev (@agirodi ), then we rebase here.
• doc/overview/FASTSURFER_EXAMPLES.md etc still exist and seem to be duplicates, check, merge (if necessary) and delete duplicates. FASTSURFER_EXAMPLES should be deleted , EXAMPLES.md kept, same with the other two.
• also doc/overview/README.md and the other md files replicate content of /README.md? So this means updating both files all the time? We need to discuss a solution for this.
• directory /doc/_static needs to be created (with .gitkeep empty file in it) as sphinx is looking for it.
• no idea what to do with the futures formatting warnings: concurrent.futures._base.Executor.map:15: WARNING: Inline emphasis start-string without end-string. , anyone? Why is sphinx even looking at those as they are not part of our project?

[dkuegler]

* [ ]  no idea what to do with the futures formatting warnings: `concurrent.futures._base.Executor.map:15: WARNING: Inline emphasis start-string without end-string.` , anyone? Why is sphinx even looking at those as they are not part of our project?

That is even a private module of concurrent.futures.

[dkuegler]

Maybe we can fix this warning with the autodoc_mock_imports directive?

Add a list of modules in the autodoc_mock_imports to prevent import errors to halt the building process when some external dependencies are not importable at build time.