Markdown is a lightweight markup language with plain-text-formatting syntax. Markdown is a way to style text inside your checklist. You can format words as bold or italic, add code blocks and bulleted lists are just a few of the things we can do with Markdown. Mostly, Markdown is just regular text with a few non-alphabetic characters thrown in, like # or *.
You can learn more about markdown syntaxes here.
Note – Markdown is disabled by default, to enable them, go to Settings > Enable Markdown.