06ba3db938
Per feedback from the support library team, updated the support library overview page to better explain what the libraries are and what they're for. This is the beginning of a big overhaul of the support library docs. The "overview" section has been rewritten and expanded in this CL. The "revisions" section hasn't been touched, except that the heading was changed to "Support Library Revision History". (I'd like to move "Revision History" to a separate page, but I'll do it in a follow-on CL.) See first comment for doc stage location. bug: 27274455 Change-Id: I12ce21c948421e1bd0be5d3151845f900750e7b1