Parametric PIR sensor box

# Parametric PIR sensor box

I started out re-mixing https://www.thingiverse.com/thing:266912, which I liked quite a bit.
My immediate need was for something with different dimensions.
However, I wanted to get familiar with OpenSCAD, so I made quite a few changes.

The permanent home of this is at https://gitlab.com/wjcarpenter/3dprinting/-/tree/main/parametric-PIR-sensor-box
This design is also published at https://www.thingiverse.com/thing:5414874

- First, there are a ridiculous number of optional features and customizations.
- Second, I reorganized and refactored the code quite a bit. The original author might have a hard time recognizing it. I did that on my way to understanding how it all worked, and also to organize things to my liking as I added the ridiculous amount of extra stuff.

Here are the features, almost all of which are optional and customizable. Dimensions are conventionally in millimeters.

- You can choose to render just the top or bottom if you don't