Keyboard: N - for note, since T is the tape measure.
How to use it
Click where the note should point.
Type it.
Move away to where the words should sit, then press
Enter.
Shift+Enter starts another line instead of
finishing.
Making it bigger or smaller
Pick the note with the select tool, then + and -. A
quarter bigger or smaller each press, between half and four times normal.
The box follows the words rather than the other way round.
Worth knowing
A note points at a place, so it keeps pointing there when you move
what it was pointing at.
Notes are drawn over everything, so one on a panel is still readable and
still clickable.
Nothing snaps to a note. They sit beside the drawing, not in it.
For a measurement that the drawing keeps up to date, use
the dimension tool instead.