Add exercises to documentation

[hypergonial]

Summary

Add short exercises to documentation to facilitate learning the different features of the library.

Why is this needed?

It helps people learn the library a lot quicker if there are potentially quick example problems to solve.

Ideal implementation

To be decided.

Checklist

• I have searched the issue tracker and have made sure it's not a duplicate. If it is a follow up of another issue, I have specified it.