add readme and upcoming comps

README.md

+comps
+=====
+
+This repository contains the comps required to build the necessary repos and
+their accompanying metadata. Each point release gets its own set of comps as
+there could be potential changes on each point release.
+
+In the event that an upstream beta has dropped, the `upcoming` folder will
+be updated. Final versions will be moved down from `upcoming` to the root.

upcoming/README.md

+upcoming
+========
+
+This is for only upcoming comps and data.