The index.rst page for Cinder was not well suited to the new openstackdocstheme that was created. This resulted in the page just looking like a disorganized set of links with no visually defined topics or explanation. With this patch I emulate the look of the Keystone page by properly indicating the different topics in the page and add some text to describe each of the sections. I also update some of the old 'Block Storage' pages to use a 'Cinder' heading for consistency. Change-Id: I341e8340b960946a86f4ff8fbee3624531b375af
Cinder Administration Documentation
Introduction:
This directory is intended to hold any documentation that relates to how to run or operate Cinder. Previously, this content was in the admin-guide section of openstack-manuals.
The full spec for organization of documentation may be seen in the OS Manuals Migration Spec <https://specs.openstack.org/openstack/docs-specs/specs/pike/os-manuals-migration.html>.