What’s Jekyll
Jekyll is a static site generator, an open source tool for creating simple yet powerful websites of all shapes and sizes. From the project’s readme:
Jekyll is a simple, blog-aware, static site generator perfect for personal, project, or organization sites. Think of it like a file-based CMS, without all the complexity. Jekyll takes your content, renders Markdown and Liquid templates, and spits out a complete, static website ready to be served by Apache, Nginx or another web server. Jekyll is the engine behind GitHub Pages, which you can use to host sites right from your GitHub repositories.
It’s an immensely useful tool and one I encourage you to use for making portfolio sites.