Streamline instructions in Quickstart

Uses the same pattern for all applied labels, brings them in a more logical order, and gets rid of the confusing re-use of the term "control plane". This was some feedback from the Summit workshop participants.

Also there is no need to give the control plane label/role to the Yaook nodes, so this drops that from the recommended list.

Drop the pointless and error-prone namespace replacement when copying the glance ceph secret.