CryptPad is a browser-based office suite like Google Workspace, and one of its document types is rich text, text that can be italics, strikethrough, subscript, ​​​​​​​and stuff.

|
|
|Who knows?|* It's worth experimenting with compatibility* But this is turning into a self-demonstrating comment|
|I'm still trying it myself|It doesn't look bad|

You can export those as Markdown.

This comment was written in CryptPad.