Notebooks in lecture 03 are in the wrong order

[luigibrancati]

The notebooks in lecture 03 - Delta Lake are in the wrong order. In particular, notebook 3.2 starts as

The cell below condenses all the transactions from the previous lesson

Referring to MERGE, INSERT INTO etc. which are covered in notebook 3.5. Considering also that notebook 3.2 and 3.3L cover topics like OPTIMIZE, I think they're supposed to be the last two notebooks in the lecture.