Create a tutorial on how to use GitHub for this working group

[CoachBirgit]

User Story:

As a contributor, I wonder how I can navigate and contribute to the GitHub repo for the DEIB working group

The Why:

GitHub might feel intimidating for contributors who are non-coders. Since the working group primarily works with documents and task management, some terms and structures might not be self-explanatory

Tangible Goal

Contributors with less experience can educate themselves by following the tutorial on how to pick a task from the issues list, how to create documents and get those merged into this repository. The tutorial also enlightens about how to utilize the Discussion and Wiki feature on this particular GitHub repository.