Pinecil stand

This stand remix has few differences which makes it firmly hold the soldering iron with the power cable connected (which adds quite some weight and offsets the center of mass):

* added an incline for the central support stem
* make the top of the stand longer
* use dovetail joint to mount the top of the stand to the bottom piece

I have printed it in PETG to count for potential thermal impact of a soldering iron.

The source code for this make is available on my [GitHub repo](https://github.com/shybovycha/cad-projects/blob/master/pinecil-stand/stand_v2.scad). Note: it uses [BOSL2](https://github.com/revarbat/BOSL2) library.