In response to rpm, will admit I’m not a fan of paying for CSS. I’m a little hostile toward these “knowledge vaults” and other custom canvas candy type things that are paid only. Don’t ask why, I just really don’t like the idea of paying for something like that, especially since I’m working with limited means. After typing this up I just realized I’m just sad I can’t buy these things because I can barely afford food and water anymore.
So the plugin that originally came to mind when I thought this was a possibility is called Obsidian Critic Markup. It’s a beta plugin and not in the community plugins list. This offers gutter / margin notes.
Anyway, this might do the trick. I’ll be playing with this and share my experiences.
Here’s the obsidian forum thread: