This commit drops contents on manila-ui, neutron-lbaas-dashboard
and trove-dashboard from the user and admin guides.
These were imported from openstack-manuals into horizon
during the doc-migration work, but they were mistakes because
they should be maintained by individual horizon plugin teams.
Closes-Bug: #1741613
Closes-Bug: #1741614
Closes-Bug: #1741615
Change-Id: I6f30cb260a23721015059c1f672b0749364033cb
Orchestration tab in the admin info panel needs a discussion.
It seems not to be covered by heat-dashboard yet.
blueprint heat-dashboard-split-out
Change-Id: I56e6edb1f2ac72e2f42d0e9f3291308e67f24cad