The source code above is an interactive live demo of Prism Syntax Highlighter for Confluence that includes (markdown) code from GitHub (https://raw.githubusercontent.com/PrismJS/prism/master/README.md). Besides including the code from the remote location the demo shows some of the other features:
Source code downloading: Click the “Download” button in the toolbar on the top right to download the source code.
Copy & paste support: Click the “Copy” button in the toolbar on the top right to copy the source code to the clipboard.
Height limitation: A height defined in the macro options (500px in this example) renders a (vertical) scrollbar.
Show invisible: Invisible characters (such as spaces and line breaks) are shown.
Clickable links: Click on the links in the source code to open the URLs in a new tab.