v3: Docs follow-ups

[GeigerJ2]

• tutorials link on aiida.net should point to RTD at support branch of the new tutorial modules
• warning on latest tutorial build (based on main), that we are breaking things, and code execution is currently disabled in the RTD build, with a link to the support branch
• banner on aiida-tutorials that content, while, in principle correct, may be outdated and not guaranteed to work anymore; include link to current aiida tutorial modules on the support branch
• dissolve former basic.md (now "provenance deep dive"), putting its content where appropriate
• add advanced tutorial modules