do not document install-qibuild scripts anymore

using pip is a better idea, and this is
the first step towards proper qibuild releases

Change-Id: I480f9b12b3145e1add662ac9425e6c55210e5d88
Reviewed-on: http://gerrit.aldebaran.lan:8080/11342
Reviewed-by: dmerejkowsky <dmerejkowsky@aldebaran-robotics.com>
Tested-by: dmerejkowsky <dmerejkowsky@aldebaran-robotics.com>