Local development of github pages using Jekyll is described here: https://help.github.com/en/github/working-with-github-pages/testing-your-github-pages-site-locally-with-jekyll
To run it locally run the following commands from project root:
bundle install
bundle exec jekyll serve
To avoid installing Ruby and Bundler, the starefossen/github-pages docker image is a good alternative. Get docker at https://docs.docker.com/
docker pull starefossen/github-pages
docker run -it --rm -v c:\path\to\open-simulation-platform.github.io\:/usr/src/app -p "4000:4000" starefossen/github-pages
For some fields you'll need a personal access token from github. See how to get it here.
To use it run the docker container with the following option -e JEKYLL_GITHUB_TOKEN=****