You can easily share any Gist code from GitHub to help show off your coding skills.
Add a New Project
Select Add Code Snippet from the sidebar.
Visit Gist and copy the URL for your code eg: https://gist.github.com/feix/6dd1f62a54c5efa10f1e1c24f8efc417
Come back to the project builder and paste the full URL into the builder.