Nth PR on develop branch for easybuild-docs, for N=5

still bits and pieces to improve, but ok to receive the first round of feedback
ok, as you wish.
As a user/sysadmin I've found the idempotent feature of easybuild one of its strongest features. I'd really like to advertise it early on, because it is THIS feature that makes it possible to integrate nicely with an existing configuration management system at the OS level...