Rework of Contributing doc. I tried to make it not too scary from a Markdown and Git perspective, and left the technical stuff at the bottom - it could be moved in a separate file.
Also, I modified the workflow description, we should discuss that.
main branch contained the latest Handbook release, work taking place on
I propose to keep working on
dev, regularly merge peer validated stuff to
main to have the latest validated version. When a release is ready, we tag it to keep a snapshot of a given release (we should tag now