Docs
* RTD: Added notebook tutorials
* RTD: Added various guides
* RTD: Added cross-references
* RTD: Cleaner navigation
Infra
* Python: Add Python 12 to CI and document support
* Docs: Udated dependencies - Sphinx 8, Python 12, and various related
* Docs: Added nbsphinx - hub url grounding, ...
* Docs: Redo as a docker compose flow with incremental builds (docker, sphinx)
* Docs: Updated instructions for new flow
Fix
* Docs: 2024
* Notebooks: Compatibility with nbsphinx - exactly one title heading, no uncommented `!`, correct references, ...