This is an archival copy of my personal website before I moved it over to GitLab Pages and made changes to support that move. In its state here, it's a good reference point for others trying to get started with Jekyll using GitHub Pages.
Note that it's possible to get many of the features that GitLab Pages supports on GitHub Pages too, such as using any gem instead of just the whitelisted ones. You'll need to use GitHub Actions to do so; you can read more about this here. If you want to read about why I moved over to GitLab Pages, check out the README for my personal website's repository on GitLab.
I use Minimal Mistakes. The website that I've based mine off of, Aakash Prabhu's personal website, uses Academic Pages, which is a fork of Minimal Mistakes. I'm no longer an academic and don't really need the extra features for Markdown generation.
Thanks to Aakash Prabhu for the inspiration behind the website layout. I have made some changes, but my layout generally follows his.