Add project doc for Pinwheel.
Merging in updates from master.

Merge branch 'master' into add-pinwheel

Conflicts:
	README.md
Adding notice about current project status (repo URL).
Merge branch 'add-pinwheel' of github.com:kreeger/summer-of-swift into kreeger-add-pinwheel

Conflicts:
	README.md
Merge branch 'kreeger-add-pinwheel'