Include Bioschemas markup in docs (use plugin)

Apply Toni's Bioschemas Sphinx plug-in to describe the TeSS Platform docs with Bioschemas

https://biocorecrg.github.io/sphinx-bioschemas/

https://biocorecrg.github.io/sphinx-bioschemas/markdown.html

We will probably have to update the `requirements.py` and `conf.py` files to include `sphinx_bioschemas`. Then add inline Bioschemas yaml to the index page.