README.md: update
Refer to doc/credits.md for parts that are better described (and up-to-date) there.
Edited by Mathieu Giraud
[A venir] Mise en place de quotas sur nos instances GitLab. Plus d'information sur : https://doc-si.inria.fr/pages/viewpage.action?pageId=129728565
[Coming soon] Quotas installation on our GitLab instances. More information: https://doc-si.inria.fr/pages/viewpage.action?pageId=129728565
Refer to doc/credits.md for parts that are better described (and up-to-date) there.