Add package-level documentation referencing the guide. am: 52c473f am: 84dc2cd am: 41b4a28 am: c4f8ab6
am: 24f85e0

* commit '24f85e08b5dead0e296a2bdb4fb343d8b5f2c08d':

Change-Id: I1ac90f01290bd83c6876024d4cc61f1cc9e0151b