Rudder

As we are grouping all Rudder plugins in https://github.com/Normation/rudder-plugins, we need to close old repository for them so that people don't go to the old, usual, now incorrect location.

We won't delete repos for now (to keep history and don't break existing scripts which may use specific tags on themp), so we will make a new commit which remove everything but the README, and that README will containt a "move" message.