New initiative to separate out docs in RTD so that the main
docs project does not have to load so many submodules everywhere.
This will put releng/builder docs at the url:
http://docs.opendaylight.org/projects/releng-builder
Also include some reference links so that we can pull these pages
from the OpenDaylight documentation project.
Change-Id: I4d6b6d693f930f61fc8889164f3ebd45b5327f81
Signed-off-by: Thanh Ha <thanh.ha@linuxfoundation.org>