Context

• This issue is not a bug report. (please use a different template for reporting a bug)
• This issue is not a duplicate of an existing issue. (please use the search to find existing issues)

Description

Currently, markdown only supports html/tag without -, which does not support <custom-component> </custom-component> properly.

<!-- correct syntax highlighting in markdown -->
<div></div>

<!-- incorrect syntax highlighting in markdown -->
<x-div></x-div>