Support for submenus

[MaxLeiter]

I'm interested in contributing this if you're open to it @james2doyle, but I want to hear your thoughts first. I'd like to support sub-menus implemented via children omnibars. You can see what I mean at https://kbar.vercel.app/ by using cmd|ctrl + k and selecting the "search docs" or "theme" options. Is there already a way to accomplish this? And do you have any thoughts on how it should be structured?

[james2doyle]

Sounds good to me. Not sure the best option for this. Since the slots don’t really support nesting at the moment. Maybe something with unordered lists? And top level UL tags?

I would be curious what you come up with on your own. Then maybe I can review. Thoughts?