Note: Docs CI warnings not turned into errors anymore

[dominiquesydow]

This issue summarizes changes made to the docs CI.

A subset of notebooks shows docs build warnings, which were turned into errors in the docs CI, although the generated HTMLs look fine.

Example:

/home/runner/work/teachopencadd/teachopencadd/docs/talktorials/T008_query_pdb.nblink:15: ERROR: Content block expected for the "raw" directive; none found.

https://github.com/volkamerlab/teachopencadd/runs/5728279025?check_suite_focus=true#step:8:36

I do not understand what is wrong - the output looks fine. If someone has an idea how to fix the root of this warning, please let me/us know.

For the time being: Warnings are not turned into errors any more as of #217, so that the docs CI stops to fail: (remove -W from SPHINXOPTS, see here): https://www.sphinx-doc.org/en/master/man/sphinx-build.html#cmdoption-sphinx-build-W

Revisit this if we do find issues with the HTML rendering.

Related issue: vladris/tinkerer#40