clarify where puppetdb is

howto/puppet.md

@@ -736,13 +736,15 @@ the future if we rely more on it for deployments.
 
 ### Before it all starts
 
-- The Puppet server is currently being run on `pauli.torproject.org`
+- The Puppet server currently runs on `pauli.torproject.org`
 - This is where the main git repository (`tor-puppet`) lives, in
   `/srv/puppet.torproject.org/git/tor-puppet`
 - The repository has hooks to populate `/etc/puppet` with its contents, most
   notably the modules directory.
 - All paths in this document are relative to the root of this
   repository.
+- The PuppetDB server - which holds all exported resources, facts and
+  reports - also runs on `pauli`
 
 Note that this layout might change in the future with the introduction
 of a role account ([issue 29663][]) and when/if the repository is made