Make a Tutorial on how to build a scheme with the updated CRTP-Approach

[Davknapp]

Feature request

The new scheme will provide much more flexibility and is a very different approach to our current approach to schemes.
A group of tutorials will help us and users to understand it and use it.

Is your feature request related to a problem? Please describe.
No

Describe the solution or feature you'd like
Idealy a step by step from beginner level to expert level of tutorials.

1. How do I use the default scheme
2. How do I build my own scheme
3. How do I implement my own eclass_scheme and add it to a scheme

Describe alternatives you've considered
Don't do it and have a bad user-experience :(

Estimated priority
Which of these is most applicable (remove the others):

"Priority: medium" Should be solved within half a year

Additional context
Add any other context or screenshots about the feature request here.