Puppet documentation updates
Puppet documentation updates

This patch updates the puppet documentation per our recent
switch to using packages installed by DIB. These instructions
should now help users to install packages at image build
time or deployment time, whichever they choose.

Change-Id: I5bfab681ea4073112aca9df7f69cf9c3db275236

rdo-management/tripleo,rdo-management/tripleo