Add an overview of the posted resources to wiki

[wshayes]

Follow up with Vy about getting a README (using Markdown or AsciiDoc for formatting) for these resources to describe how they were created (how the Evidences were selected for the two corpora), basic stats of the corpora, etc) - should pretty much duplicate what is found on the OpenBEL Wiki. It might make more sense to remove the Wiki page content (mostly) and link to this document in the repo.