Fix bullet list format in README.rst

Change-Id: I3cbf36745a6c39c2a06d5522ffd7424e80f3f278
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: Ib65ea472a4503a19c10ceabd8835b17e069d0dde