The official Jekyll docs recommend the best way to install Jekyll is via RubyGems. I have covered everything here for someone getting started with a Jekyll blog, all the necessary Git commands and steps to deploy to Github Pages. No need to manage containers, servers or databases.
Saying "Don't do this" is a little harsh as knowledge of Docker is really not necessary. Using Docker is more of a personal choice thats suits your workflow.
I don't think this is the case anymore tho, as you can use two commands `brew update` to update Ruby and `bundle update` to manage Jekyll.
- Homebrew does a great job of managing Ruby versions on macOS.
- Bundler now manages all of Jekyll's dependencies without issue.
Here's a challenge for you. Write a companion article about testing a GitHub Pages blog on a Mac without installing Jekyll. Instead, run the Jekyll server in a Docker container. I don't think anyone else has written a good article on this topic, and I think it would complement your original post nicely. Good luck!