Add a CONTRIBUTING.md

[sdesrozis]

Hi the team !

A guide to contributions would be very helpful. Actually done in the README which would be a show case of the lib.

For instance

• Quickstart guide for first-time contributors (Create a fork, send a PR, etc.)
• Code development (Codebase structure, formating, run tests, etc.)
• Writing documentation
• Etc.

[sdesrozis]

The bug label was automatically added, I can't remove it.

[cedricchevalier19]

It is definitely something to do but we have to strengthen our workflow before. We had trouble running CI with forks etc.