[Doc] Quick Start ( was Put a link towards the Rescom17 Lab)

[rcherrueau]

No description provided.

[msimonin]

We are now able to build on demand vm for this kind of lab (see tests/functionnal/vagrant/packaging). the resulting box can be uploaded to vagrantcloud :

https://app.vagrantup.com/discovery/boxes/enos

In my opinion we should document a quick-start in the doc based on the lab.

Note on the versions of the boxes:

we could use the patch version number (Z in X.Y.Z) when iterating on the code of the box generation and reserve the minor version number (Y in X.Y.Z) when we patch enos code.

cc @denaitre