support: fix header levels and names

support/getting-started.rst

 .. _beagleboard-getting-started:
 
 Getting Started
-##################
+==================
 
 Beagles are tiny computers ideal for learning and prototyping with electronics. 
 Read the step-by-step getting started tutorial below to begin developing with your Beagle in minutes.

support/index.rst

-Overview
-========
+.. _support:
+
+Support
+#########
 
 .. note:: #TODO# all the links need updating and content moved into this repo.