Function / package to permanently highlight a selection

I use Atom as a markdown editor for non-code text. I would like to be able to highlight…

  1. …a selection of characters (one word, several words, a random string etc) by underlining or “background-coloring” them,
  2. …group those highlights into categories where each category has it’s own color,
  3. …and most importantly make those highlights permanent (so that they still exist after I shutdown Atom). None of the packages I found supports this. Is there a structural reason for this?
  4. …nice to have would be to toggle all highlights on/off.

This does what I want except for 2), 3) and 4).

Is anyone aware of how to do that?

PS: I deleted and resubmitted this topic because I couldn’t edit the post. Why is there not editing function (probably I just don’t see it)? :slight_smile: