System dependencies

[rmeissn]

There is a Dockerfile in this repository. May I ask why:

1. you base on ubuntu 21.04 instead of e.g. ubuntu LTS (22.04) or better node:lts
2. you install node14 (instead of LTS)?
3. you install build-essential? It doesn't appear you use make or gcc at all
4. you install python? There appears to be no python code in this repo