Fix bullet list format in README.rst

Change-Id: I30a056dcb1f61eb3049d920ec90df89e5fd48a63
Ignore publish-docs directory

Ignore publish-docs directory. This is the directory used by
openstack-doc-test to copy draft documents to.

blueprint draft-docs-on-docs-draft

Change-Id: I5068eaa8105b003a43d7e909de447920d649451b