Egonomic parametric THC scraper/spoon

Made by request: This is a spoon/scraper combo, intended to aid in the collection of THC crystals from a cannabis harvest. Two versions are included, short and long. The long one is 245 mm long, which should fit on most build plates.

Features:
- ergonomic handle, comfortable to hold
- a spoon on one end
- a scraper on the other end
- scraper is sharpened on three edges
- top of the scraper is recessed to serve as a scoop

Basically I made this as a reason to figure out the 3D problem of making a square spoon with a round bowl, which I had been wanting to do for a while but never had a practical use until now. The spoon profile is known as a "squircle", a hybrid between a square and a circle controlled by a squareness parameter ranging between 0 (circle) and 1 (square).

Everything is parametric in the `thcspoon.scad` file, if you want to change anything:
- Spoon length, width, depth, and squareness
- Handle width, height, and length
- Scraper width, length, and thickness