[SCAD] GoPro thread screw butt plug (customizeable)

IMPORTANT: Print at 99% scale. I have not be able to add tolerances in. Local copy of openscad has a bug where fast-csg dies on scaling.

Hex filler butt plug for gopro thumb screws.

Why: Harbor Freight M5 bolts would sit loosely inside these thumb screws.

Make a butt plug so it can be secured (by friction).