Feature request: allow highlighting notes for future follow up

[thomasmeeus]

Have you searched existing Github issues to see if someone has already requested this feature?
Yes, didn't find anything related

Is your feature request related to a problem? Please describe.
I use Heynote for storing all kinds of notes e.g things to not forget, temporary documentation, drafts, but also meeting notes. Sometimes I write down a note on which I have to act on, at a later point in time. Currently it's only possible to find the note back by searching on keywords you remember, or by diagonal reading the entire notepad

Describe the solution you'd like
imho it would be nice if we could add markers to identify notes that require a follow up. I see 2 possible options that I would use:

• add a marker to highlight an entire note. This would change the background color to something that's easiliy recognized while scrolling. It would be nice if the background color can be configured in the settings.
• add a marker to line numbers. This can e.g. be a red dot before the line number or change the color of the line number itself in the sidebar.

Describe alternatives you've considered
Currently I enter the keyword 'todo' in my notes for things that require follow up. This works, but can obvisouly be improved with my suggestion.

Additional context
Big ❤️ for Heynote