Add reference to launchpad in the README.rst
Add reference to launchpad in the README.rst

Change-Id: If70ead14478d8809fde229b912080a26f9ed4ce6

open-power-ref-design-toolkit/os-services,open-power-ref-design-toolkit/os-services,open-power-ref-design-toolkit/os-services,open-power-ref-design/os-services,open-power-ref-design/os-services