Update features and reference for mezzanine-project in README.
Update features and reference for mezzanine-project in README.

Parisson/cartridge,Kniyl/cartridge,wbtuomela/cartridge,ryneeverett/cartridge,traxxas/cartridge,wbtuomela/cartridge,ryneeverett/cartridge,wyzex/cartridge,viaregio/cartridge,dsanders11/cartridge,syaiful6/cartridge,stephenmcd/cartridge,syaiful6/cartridge,stephenmcd/cartridge,wyzex/cartridge,jaywink/cartridge-reservable,Parisson/cartridge,wbtuomela/cartridge,Kniyl/cartridge,traxxas/cartridge,syaiful6/cartridge,stephenmcd/cartridge,Kniyl/cartridge,viaregio/cartridge,wyzex/cartridge,ryneeverett/cartridge,Parisson/cartridge,jaywink/cartridge-reservable,traxxas/cartridge,dsanders11/cartridge,dsanders11/cartridge,jaywink/cartridge-reservable