gerritbot: Add API doc git notifications on #openstack-doc

This patch aims to add more repositories on #openstack-doc IRC channel.

Change-Id: If4de511a61cb0555818ae1a600d48de585745e91
Signed-off-by: Emilien Macchi <emilien.macchi@enovance.com>
Merge "gerritbot: Add API doc git notifications on #openstack-doc"