docs: add ceph telemetry design doc
docs: add ceph telemetry design doc

Add a design doc for adding Rook telemetry to Ceph telemetry capture.

Signed-off-by: Blaine Gardner <135b86f2968bdbcc730c10d8ababd343bb675986@redhat.com>

rook/rook,rook/rook,rook/rook,rook/rook,rook/rook