Customizable Xmas Wreath

This Christmas wreath is made out of pieces that are intended to look like (stylized) spruce twigs. The "twigs" can be either laser cut or 3D-printed.

Parameters that can be customized:
* _wreath radius_ determines the size of the wreath
* _number of twigs_, there must be an even number of pieces
* _thickness_ of the twigs. How thick to make 3D-printed twigs. When laser cutting: the thickness of the material.
* _show assembled_ shows the entire wreath rather than one twig. You gotta have a bit of patience to use this option. Rendering a big wreath with many twigs takes a long time.

The attached STL and SVG files correspond to the initial parameter settings (what you get when clicking _Open in Customizer_): 200 mm radius (i.e. 40 cm in diameter), 24 twigs of 3 mm thickness. STL is meant for printing and SVG for cutting,