* Update required message types and add v2.0 ex.
Changed wording of section listing required message types to make more clear the necessity of sending V_STATUS messages along with V_PERCENTAGE or V_RGB messages. Also, added a MySensors v2.x example sketch which is substantially different from v.1.x. Example sketch taken from MySensors github repo with some comments removed.
* Updated example sketch
Simplified and style corrected.
* V_LIGHT changed to V_STATUS ...
Updated to use non-deprecated types. Also updated library link.
* Updated wording of type description
Updated description of which type messages to send in response to events. This is a hard requirement to fully explain, but hopefully the example sketches will provide guidance.
* Add binary sensor page. Move door, motion, smoke, and part of
sprinkler, leak, sound, vibration and moisture sensors to binary
sensor from sensor page.
* Move back S_LIGHT to switch page from light page.
