Merge "Merge "Docs: Adding information to Building-for-Billions landing page." into nyc-dev am: 410ae5b004 am: e5036b3cab am: d6ad4f051e" into cw-f-dev
am: 5d653c4771

Change-Id: I81255bcdec7563b1fe9d9ea05bca67cf4a47e291