Tor HS info

A few additional commits on top of https://github.com/freedombox/Plinth/pull/15.

Add a subcommand to the tor action to get hidden service information (hostname and ports) from current Tor configuration. Display this information in the Tor module page. Also reorganized the Tor page.

TODO: Ability to add or modify the Tor hidden service is not implemented yet.

Updated docs to fix a few issues I had run into while testing https://github.com/freedombox/Plinth/pull/14.