Switch from sphinx to use mkdocs

[ens-LCampbell]

• Initial set up configs
• Workflow update
• MD file creation
• auto docs gen_reference MD script
• Revert sphinx to backup and update build script
• Update project TOML for mkdocs/sphinx distinction

[JAlvarezJarreta]

I would personally drop docs/sphinx/source, scripts/setup/docs/build_sphinx_docs.sh and the sphinx label in pyproject, but besides that great addition 📜 I have done just a few minor suggestions on code cleanup and such.

I have a feeling some of these documents could be pulled from their original source to be generated/updated, e.g. license.md, but that can be done in a later stage (if needed).

Note: unless it is required to be this way, mkdocs.yaml should be mkdocs.yml

[JAlvarezJarreta]

Same as before.

[ens-LCampbell]

I've removed the versioning information, changed the name to Ensembl GenomIO. Also removed Sphinx legacy scripts, source etc as suggested. If we can get from git history then fine by me.

[JAlvarezJarreta]

Unless there is a way to pull the version information from the Python code, I would be reluctant to have it here as it is really likely we forget to update this at the same time as in the Python code (unless we add a check for it).

[JAlvarezJarreta]

I guess we either want to do Ensembl GenomIO or ensembl-genomio ("official name" vs pypy library).

[JAlvarezJarreta]

Looks quite neat 👀