A default Jekyll installation, except with tags and categories designed to work with GitHub pages.
Much credit to Minddust.com for explaining how to set this up. I used this post’s instructions in configuring my own site.
I tried to keep this as close to ‘out-of-the-box’ Jekyll as possible. That said, I added category and tag metadata to the bottom of the post.html layout, and styled the blog_by_category and blog_by_tag layouts in a way I thought was consistent with the default set-up.
You may wish to link to category pages in the menu, or have the categories in a post link to their respective pages. I didn’t want to make those decisions for you—this is a bare minimum set-up to have category and tag pages on GitHub pages, but you’re implementation will be up to you.
Best wishes!