Add SUPPORT file

[jmakeig]

https://help.github.com/articles/adding-support-resources-to-your-project/

Content TBD.

[popzip]

Update Open Source Support language:

Please refer to updated text for DHF, included below as point of reference. Key changes are to say "made available under...", reference "TechnicalSupport Handbook". Change anything specific to another product (eg DHF). The rest should be pretty boilerplate/straight copy paste.

use Support.md attachment from internal wiki on "Open Development and Open Source"