Merge "cherrypick I4e1ca9fddc6374fd80108e4f9a3b9745f8598507 add new make target for offline docs with only the API reference. Also update the default index.html landing page to redirect to the reference." into nyc-dev am: b907ff764a
am: 76576fad9a

* commit '76576fad9a98e12e36213bc83808cd6eb540d20d':
  cherrypick I4e1ca9fddc6374fd80108e4f9a3b9745f8598507 add new make target for offline docs with only the API reference. Also update the default index.html landing page to redirect to the reference.