Hello - it would be very useful to have a 'header' - I'm not sure what to call it - like 'Special instructions', but for the annotated solutions. This would be handy for things like 'The theme is X', or other comments that apply to the puzzle, but not to individual solutions, and are spoilers.
That's a good shout, I'll add it to my list and have a think. Could look something like the attached file.
The other thing that the annotations are missing is the ability to highlight the definition (e.g. underlined) but that's a little trickier as I'd have to make a more sophisticated text input - one for another time perhaps.