Upgraded Precious-Plastic shredder

This is the latest version v3.4 (October - 2021), based on PreciousPlastic v2.1 design.

## Features

- Jam detection
- Rigid, flexible and modular framework – enabling hacking and extensions
- Electronics and wiring according to standards
- Auto-Stop after being idle
- Visual feedback
- 5mm sieve, easy to remove for cleaning