Hugo uses Markdown for its simple content format. However, there are a lot of things that Markdown doesn’t support well. You could use pure HTML to expand possibilities.
But this happens to be a bad idea. Everyone uses Markdown because it’s pure and simple to read even non-rendered. You should avoid HTML to keep it as simple as possible.
To avoid this limitations, Hugo created shortcodes. A shortcode is a simple snippet inside a page.
The Relearn theme provides multiple shortcodes on top of existing ones.
Badge
Marker badges to display in your text
Button
Clickable buttons
Children
List the child pages of a page
Expand
Expandable/collapsible sections of text
Highlight
Render code with a syntax highlighter
Icon
Nice icons for your page
Include
Displays content from other files
Math
Beautiful math and chemical formulae
Mermaid
Generate diagrams and flowcharts from text
Notice
Disclaimers to help you structure your page
OpenAPI
UI for your OpenAPI / Swagger specifications
Resources
List resources contained in a page bundle
SiteParam
Get value of site params
Tab
Show content in a single tab
Tabs
Show content in tabbed views