Add bootstrapping and puppet apply to puppet doc

Updated the puppet documentation to reference usage of puppetlabs repos and
basic instructions for bootstrapping the puppetmaster environment so that
puppet apply can be used to complete configuration.

Change-Id: I250e00c9bc128438378558e39f23109f9880386c
Reviewed-on: https://review.openstack.org/20048
Reviewed-by: Clark Boylan <clark.boylan@gmail.com>
Approved: Jeremy Stanley <fungi@yuggoth.org>
Reviewed-by: Jeremy Stanley <fungi@yuggoth.org>
Tested-by: Jenkins