Add Spaced Repetition, Resistant Moves, Errors etc for drills

Some drills I'm able to solve first-time because I know the content well. Some drills, or some moves, I struggle with and need to revise more. Various tools for this are common elsewhere (e.g. chesstempo) but I don't see them on Chessly, so I need to use a notebook to write down what drills I did well on or not, to track my practice.