Jekyll is pretty cool. I followed the Quickstart guide which generates a basic blog site using the minima theme. Once you push the source to your https://github.com/<username>/<username>.github.io repo, Github Pages will build your site and make it available online at <username>.github.io. You can see what the site looks like locally before pushing by running bundle exec jekyll serve --drafts and pointing your browser at 127.0.0.1:4000.

To add a new post, one simply pushes a markdown formatted post to the _posts directory that follows the convention YYYY-MM-DD-name-of-post.md and includes the necessary front matter. Take a look at the source for this post to get an idea of what the front matter looks like.

Jekyll also offers powerful support for code snippets:

#include <iostream>
  
int main(void)
{
  std::cout << "Hi, Tom.\n";
  return 0;
}
// prints "Hi, Tom." to stdout.

Inline tables look like so:

Priority apples Second priority Third priority
ambrosia gala red delicious
pink lady jazz macintosh
honeycrisp granny smith fuji

Inline figures look like so:

Inline math look like so:

The GitHub help page on setting up your github pages site locally with jekyll might be useful. Check out the Jekyll docs for more info on how to get the most out of Jekyll and the source of the minima theme to see what a complete Jekyll site looks like. If you have questions, you can ask them on Jekyll Talk.