Add a Cinder guide
Add a Cinder guide

Based upon Paul's work with Swift documentation, I decided to
add a bit of Cinder documentation since Cinder isn't totally obvious.

Change-Id: I502d88200ae9fd0e8a87d9981424903be9612cd5

GalenMa/kolla,stackforge/kolla,fdumpling/kolla,rajalokan/kolla,mandre/kolla,mandre/kolla,dardelean/kolla-ansible,chenzhiwei/kolla,chenzhiwei/kolla,openstack/kolla,limamauricio/mykolla,rajalokan/kolla,negronjl/kolla,tonyli71/kolla,stackforge/kolla,toby82/kolla,GalenMa/kolla,intel-onp/kolla,coolsvap/kolla,rahulunair/kolla,coolsvap/kolla,fdumpling/kolla,mandre/kolla,toby82/kolla,chenzhiwei/kolla,tonyli71/kolla,limamauricio/mykolla,intel-onp/kolla,negronjl/kolla,fdumpling/kolla,toby82/kolla,nihilifer/kolla,rahulunair/kolla,limamauricio/mykolla,dardelean/kolla-ansible,dardelean/kolla-ansible,stackforge/kolla,coolsvap/kolla,mrangana/kolla,rajalokan/kolla,negronjl/kolla,nihilifer/kolla,openstack/kolla,mrangana/kolla