Markdown doesn't have a comment. There are eleventy bazillion different ways of simulating a comment by abusing things to effectively hide a chunk of text, but they are all very sensitive to which Markdown renderer you are using. The safest bet is a
<div> with a style that sets
none. The <> class does this:
some text that you don't want to appear in the document
The text is still in the HTML, so don't use this to hide anything sensitive.