v1.0.1 - Update to node 20, fix build error

This upgrades us from node:12-slim to node:20-slim, which also updates the underlying Debian image to be based on Buster - Solving build errors due to some mirrors not being around for Stretch any longer.

1.0.0 - Initial working version

This is the initial working version. It works exactly as intended, no reason to faff about with alpha versions or such.