Add release guide.
Add contribution guide.
Mention release and contributions guides in README.
Add projections file.
Update CHANGES.
Revert "Add projections file."

This reverts commit c497a7a3d5ff6568e16d4e6faed60f841a79ed09.
Remove reference to projections file from CHANGES.
Merge pull request #50 from contextio/bh/standard_docs_and_cetera

Spruce up Docs a Little