FYI: Instead of the "old / out-dated" Jekyll Now setup by Barry Clark (before packaged themes arrived on GitHub Pages) - you can use the Minima theme (default) and get started in 60 seconds. See Hello, Minima! Theme - Get Started in 60 Seconds @ https://github.com/henrythemes/hello-minima-theme as a ready-to-fork (live) example.
PS: For more ready-to-fork (open source) themes for GitHub pages, see the Dr Jekyll Themes directory / listing (200+ and counting) @ http://drjekyllthemes.github.io
PS: For more ready-to-fork (open source) themes for GitHub pages, see the Dr Jekyll Themes directory / listing (200+ and counting) @ http://drjekyllthemes.github.io