Update the list of guides in README.rst
Update the list of guides in README.rst

Remove the security and training guides.
Add the CLI and config references.
Sort the list

Remove mention of gating tools.

Change-Id: I5e30d079e934c5c8bf1d57d3fe98fb15178d87ab

openstack/openstack-manuals,potsmaster/openstack-manuals,saeki-masaki/openstack-manuals,kairoaraujo/openstack-manuals,gongysh2004/openstack-manual,gongysh2004/openstack-manual,saeki-masaki/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,Akasurde/openstack-manuals,Akasurde/openstack-manuals,potsmaster/openstack-manuals,kairoaraujo/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals