When the code compiles and completes CI:

Embed links to your programs into your guides. Only the .ino file for the main program need be embedded.

Where you want the code, choose the Embed Element:

In the the dialog box that follows, choose URL, in which you will use the web address for the .ino file in GitHub:

Use the URL provided by the facilitator. When done, you can use the guide preview function to see how it looks. If you get an error "Unable to display", use the browser refresh button.