For local development you can simply start a jekyll server via docker:
$ cd weuc.eu/
> docker run --rm --volume="$PWD:/srv/jekyll" --volume="$PWD/.gems:/usr/local/bundle" -it -p 4000:4000 jekyll/jekyll:4.0 jekyll serve
ruby 2.6.5p114 (2019-10-01 revision 67812) [x86_64-linux-musl]
Configuration file: /srv/jekyll/_config.yml
Source: /srv/jekyll
Destination: /srv/jekyll/_site
Incremental build: disabled. Enable with --incremental
Generating...
Jekyll Feed: Generating feed for posts
done in 1.668 seconds.
Auto-regeneration: enabled for '/srv/jekyll'
Server address: http://0.0.0.0:4000/
Server running... press ctrl-c to stop.
The site is then available under http://127.0.0.1:4000/