This is a page with the image-modal included. The page needs to be a .html page instead of markdown.
You can click on the image to see a larger version in a modal.
The below snippet shows an example of how to include the image modal.
{% include image-modal.html ratio="is-16by9" link="https://via.placeholder.com/400x225" alt="Example image" large_link="https://via.placeholder.com/1200x675" %}