[Feature] highlight black/white keys for newbies about pianofromabove

[Keeper1st]

It already makes the white keys thicker than the black keys. What I'd like to see is a proper piano-roll view when the keyboard is not displayed, i.e. all notes the same width and the same distance apart, so that a B and C are not twice as far apart as a C and C#. They're the same interval so should be the same distance apart, with all notes the same width. If it could play the notes in the middle of the screen instead of the bottom, that would make it even more like a piano roll.