Move away from Jupyter notebooks

[ageorgou]

Notebooks are very suited for demonstration, but not ideal when it comes to maintaining and reusing the material. We have for a while discussed switching to another system, such as Sphinx. This is for tracking ideas and notes.

Sphinx

• Initial attempt in #155.
• Source in reStructuredText.
• Allows search.
• Can render UML diagrams written in mermaid through a plugin.

[p-j-smith]

Other options that may be worth exploring:

• mkdocs - similar to Sphinx but uses markdown rather than restructured text (although there's an extension to use markdown with Sphinx)
• Jupyter book - would still mean using notebooks, but there's an extension to create books from regular Python scripts rather than notebooks
• quarto - uses it's own qmd file format, although Python scripts and notebooks can also be used
• workbench - new lesson template for Carpentires courses; allows two different views of a lesson - one for students and another for instructors
• nbfancy - similar to our process, but no homebrewed