The source of the Apache Wicket website, built with Jekyll. The branch asf-site holds the source and, in content/, the built site that the ASF web servers publish.
Run it on your machine with Docker or Podman:
docker run --rm -it -p 4000:4000 -v "$PWD":/site:z -w /site ruby:3.3 \ bash -c "bundle install && bundle exec jekyll serve -H 0.0.0.0 -d /tmp/site"
and open http://localhost:4000. Build the site for publishing with bundle exec jekyll build, which writes content/.
The contributor documentation on the site explains the rest: https://wicket.apache.org/contribute/, starting with Make your first change to the site.