Update developer's guide

[rsmmr]

Includes:

• Rework and update developer documentation's architecture diagram. This is now generated through Python's diagrams package (i.e., graphviz). Because the layout is automatically determined by dot, it's not perfect; but seems good enough.

• Update debugging streams.

• Remove benchmarking section, as this was completely outdated.

[rsmmr]

I'll make a quick cleanup pass but honestly, I don't it's a good use of time to dig too much into the details here. The content is the diagram, not the Python script. :-)

[bbannier]

I'll make a quick cleanup pass but honestly, I don't it's a good use of time to dig too much into the details here. The content is the diagram, not the Python script. :-)

The new diagram is great, I reviewed the content 😉