doc: Further cleanup of doc contributor guide
doc: Further cleanup of doc contributor guide

Change-Id: I03f00876fd8a51af487b18b8eb3f53454f81f0a2

openstack/nova,mikalstill/nova,klmitch/nova,mahak/nova,rahulunair/nova,gooddata/openstack-nova,gooddata/openstack-nova,openstack/nova,phenoxim/nova,klmitch/nova,klmitch/nova,rahulunair/nova,phenoxim/nova,mikalstill/nova,gooddata/openstack-nova,rahulunair/nova,mahak/nova,gooddata/openstack-nova,openstack/nova,klmitch/nova,mahak/nova,mikalstill/nova