Update studio landing page and add all-new install flow docs. bug: 27850063...

Update studio landing page and add all-new install flow docs. bug: 27850063 (update system reqs for 2.0) bug: 27725026 (update download page for 2.0) bug: 23908299 (clean up download and get started) am: 9577d31b am: fc35cf2c
am: 478463ac

* commit '478463ac':

Change-Id: I1788b6e613ecd7ae3850dd5fc838787efab7387a