Update sorting section of the tutorial

[gdementen]

https://larray.readthedocs.io/en/stable/tutorial/tutorial_transforming.html#Sorting

• Use 1D examples first (or only?)
• Add example of sort_values(axis=)
• do not show example of sort_values(key=) (it seems extremely niche to me)

@alixdamman : What do you think about these points?

[alixdamman]

Use 1D examples first (or only?)

It doesn't hurt to have 2 examples: 1D and 2D

Add example of sort_values(axis=)

OK

do not show example of sort_values(key=) (it seems extremely niche to me)

I hesitate. It doesn't hurt to know that it exists but we should limit to a 1D example.