You can use Markdown "a lightweight markup language" as defined at Wikipedia, when creating the templates for your Infowindow and Listing content
The goal is to write a template in plain text format including your data within {{datasheet-header}} placeholders, that would later render as rich HTML content
The Markdown template is a (premium) option for the Infowindow and the default option for the Listing (see more on Preferences under Infowindow and Listing)
On the add-on Preferences under Infowindow and Listing, there is a Markdown editor with a realtime rendering view
There is a lot of documentation about Markdown and at the bottom of this page we include some relevant links as well
Otherwise, we can also "learn by example(s)" or in other words "copy - paste - try -edit - done"
In addition / combination with the standard Markdown you can also use simple html markup if you feel comfortable doing that.
Find below some examples just as a reference
### {{Name}} ({{Choice}})
{{Category}} >> [{{Feature}}]({{Extras}})

> {{Notes}}
<div style="position: -webkit-sticky; position: sticky; top: 0px; background-color: white; padding-bottom:5px;">
## {{Name}} ({{Choice}})
</div>
{{Address}}
[More details on {{Feature}}]({{Extras}} " ")\
[]({{Picture}})
> {{Notes}}
### {{Name}} ({{Choice}}, {{Range}})
{{Category}} >> with [{{Feature}}]({{Extras}}) feature
> {{Notes}}
As a Markdown parser and compiler, we are using marked (documentation, demo and library)
As a sanitizer for the HTML output we use DOMPurify (library and documentation)
Also available the GitHub Markdown style as a CSS file (style-sheet and demo page)