HDZero Whoop vtx adapter

This is a mounting adapter for the HDzero Whoop vtx, to be mounted on top of a 20x20 stack. The vtx is held in place just by screwing four M2 Screws down into the TPU filament. The holes are m2 for both the stack and vtx mounting.

Two versions:
- HDZero_WhoopAdapter: with taller standoffs.
- HDZero_WhoopAdapter_Grommets: With shorter standoffs, so you can use rubber grommets for soft mounting. (See picture).