Promotion puzzles

[ddugovic]

Is your feature request related to a problem? Please describe.
Players sometimes have difficulty reading and evaluating breakthroughs to promote one or more pieces.

Describe the solution you'd like
Allow for "promotion" puzzles (user-submitted or otherwise).

Describe alternatives you've considered
Have some sort of training materials about common breakthroughs.

Additional context
This "promotion" exercise is similar to one from Maurice Ashley Teaches Chess (1995) where the object was to break through the opponent's pawns to promote a pawn.