smarthome/local: update README
smarthome/local: update README

- update label for Actions on Google console instructions.
- re-organize functions and devices examples to match.

Change-Id: I0323dba29a6f5823c51c8f740a28c856109655d1

actions-on-google/smart-home-local,actions-on-google/smart-home-local,actions-on-google/smart-home-local