Since there's already a hint on how to tell the bot to book a room,
and some people have been slightly struggling with updating track
info, add a couple of hints making it more obvious how to do this
without having to consult a larger README.rst. This should hopefully
encourage more people to help keep track info up to date.
Also include a link to the nicely rendered version of README.rst on
GitHub, so that if people are looking for more detailed help, they can
easily find it.
Change-Id: I3596d69dc84b635bc3a67ff7223a7ccfad27308e
<pclass="text-muted">Content on this page is being driven by room operators through the <ahref="https://github.com/openstack/ptgbot/blob/master/README.rst">openstackptg bot</a> on the <ahref="http://eavesdrop.openstack.org/irclogs/%23openstack-ptg/">#openstack-ptg IRC channel</a>. It was last refreshed on {{timestamp}}.</p>