Add python-scripting tutorial for documentation

[banchan86]

The python-scripting documentation could benefit from a tutorial with some concrete examples. The example from https://github.com/orgs/bonsai-rx/discussions/2027 could be a good starting point, but that example I think could actually be implemented with regular bonsai operators. It would be good if the tutorial showcased an example that would be hard to achieve with regular bonsai operators (using one of the python libraries like scipy for instance for specialized processing).

Basic outline:

• Basic example (print "Hello World" on a KeyDown or Timer for instance)
• Intermediate example (script that triggers on a ROI detection in video)
• Advanced example (signal processing with scipy)