Camera rig feet for 15mm rails

Design allows you to snap them into place without having to de-rig everything.

Fits smallrig, but will fit any 15mm rail system where they are 60mm apart.

Just added a model that makes the rails sits 0.8 inches higher. Some people that are using handles commented that the original size didn't give the clearance for the handles. 0.8 inches should work for all cases.