Add more concrete & complete examples in the tutorial that would interest our users

[gdementen]

Something like "Python for Econometrics" should be an inspiration. It's a bit messy (order of chapters seems weird to me), but it covers a lot of stuff.

https://www.kevinsheppard.com/images/0/09/Python_introduction.pdf

[alixdamman]

FYI: I have tested nbsphinx extension to parse Jupyter notebooks and it works (on LArray usage at least).