If you use Jekyll as a static site generator with GitHub Pages, you benefit from more support with setting up, updating, and troubleshooting your site.
About GitHub Pages and Jekyll
In addition to supporting regular HTML content, GitHub Pages supports Jekyll, a popular static site generator.
Setting up your GitHub Pages site locally with Jekyll
You can set up a local version of your Jekyll GitHub Pages site to test changes to your site locally. We highly recommend installing Jekyll to preview your site and help troubleshoot failed Jekyll builds.
You can configure most Jekyll settings by editing your _config.yml file.