Pvillads/adding schema

[pvillads]

Pull Request Template

Description

This branch contains the first version of the YAML schema for the test files, and some changes to the text files that explain what each tag means.

Checklist

• The code change is covered by unit tests. I have added tests that prove my fix is effective or that my feature works
• [ X] I have performed end-to-end test locally.
• New and existing unit tests pass locally with my changes
• I have commented my code, particularly in hard-to-understand areas
• [X ] I have made corresponding changes to the documentation
• My changes generate no new warnings
• I used clear names for everything
• [ X] I have performed a self-review of my own code