- Document the authoritative place for our Puppet modules
   and the synchronization mechanism to the public mirrors.
 - Clarify what's the manifests repo and its use of submodules.
 - Avoid pointing non-sysadmins to doc that won't work for them.
 - Point to the Puppet modules Git repo doc from contribute/how/sysadmin.
 - Make the link to our Puppet code more obvious on
   contribute/working_together/roles/sysadmins