docs(README): add infos pratiques
feat(submodule): add legacy projects

* atelier-arborescence-pstopdf
* atelier-autocompletion
* atelier-lire-l-aide
* atelier-preparer-un-environnement-collaboratif-tmux
* atelier-tmux
* donnees-pour-les-ateliers
Merge branch 'master' of github.com:Labx/cli-labx

Conflicts:
	README.md