I decide … write a custom Hugo shortcode to support using GLightbox. Custom shortcode? Shortcode? If you’re not familiar with this part of Hugo, the static site generator that powers Micro.blog under the hood, well you’re not alone. A shortcode is a Hugo-specific extension to your Markdown posts so that using a specific syntax you can dynamically create complex HTML content.

Source: Using GLightbox with custom Hugo shortcodes on Micro.blog.