doc: Add Onscreen to the party
doc: Add Onscreen to the party

It was sad and crying in a corner.

djdeath/cogl-android,djdeath/cogl,djdeath/cogl,gcampax/cogl,gcampax/cogl,djdeath/cogl-android,djdeath/cogl,gcampax/cogl,gcampax/cogl,djdeath/cogl-android