DOC: Add more examples for Series resampling in tutorials

[Winterflower]

It would be nice to see more resampling examples in the Tutorials section here.
Some examples I am working on for this:

• example using custom how function
• example showing how to use base

[jorisvandenbossche]

And more here: #5023

[jorisvandenbossche]

Let's add the different items there.

[jorisvandenbossche]

@Winterflower if you see more items to improve, just add it as a comment to the other issue. And certainly feel free to tackle some of those!