Parametric weaving loom heddle

## EDIT 2023-12-18: I've converted this to a WIP -- a bunch of test prints caused me to revise a bunch of bits. I'll update the files soon!

A parametric heddle generator for ten16's famous [rigid heddle loom](/thing:490467). Inspired by the fact that my printer's build volume is too small for the original heddle, I decided to make the whole thing parametric so you can make your own variable-dent heddles. For example, you can mix-and-match a 2-inch-long, 6-dent reed with a 1-inch-long, 12-dent reed in a repeating pattern, string them onto a set of dowels, snap the end caps on, and go for it. Then you can pull the thing apart, string a bunch of 8-count reed panels on there, and weave a more conventional piece.

All the pieces are symmetrical, and everything is held together using pressure fittings -- the dowel holes are sized to slip on snugly, and there are additional mortise-and-tenon fittings to keep everything from slipping. There are also optional screw holes on the dowel end c