Add (interactive) Software Framework/Extensions Diagram

[michaelweinold]

@romainsacchi recently added 6745788 a helpful diagram:

We could just add it to the Software Framework page (which might benefit from a more helpful name)... but it would be better to add it as a Mermaid (or similar) diagram.

[michaelweinold]

Related:

• {mermaid} Directive Broken executablebooks/MyST-Parser#979
• Add click interactions to MindMap mermaid-js/mermaid#4099