Customizable everything box (waterproof)

### Version 1.2 (2025-03-12)
* Added TPU inset print option
* fixed some bugs
* updated description

Well, it has been some years already that this box model is online, and that people seem to like and use it. Always happy as a designer to see that happen.

Recently, a reader suggested to add an option for a (TPU) inset model so that the oddly shaped isolation rubber for the "ditch" could be self-printed. I absolutely see this as a great idea and added it.

There are now two more Customizer parameters:
1. **TPU inset**: Setting this to non-zero adds the model for the rectangular "ring" meant to be printed with TPU/TPE/soft material. The parameter sets the height for this inset, and at the same time reduces the wall height on the main box model for the same amount.
2. **TPU inset X/Y reduction**: Setting this parameter to non-zero reduces the width of the TPU model so that it can be installed easier into the ditch.

### Version 1.1 (2016-08-21)
* added customizer tags and made it custom