This patch adds information about default volume types i.e. project
default and deployment default (set via default_volume_type in cinder.conf)
and also regarding __DEFAULT__ type.
Change-Id: I47151b621003aea04082d38bd1d5cc911afab0f4
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.