Feature: configurable downranking

[OccTherapist]

It would be awesome if there were a board method like ->downrankable().

Right now it throws an exception if you try to drag a card into a lower rank.

It throws in the Rank Class:

    public static function betweenRanks(self $prevRank, self $nextRank): self
    {
        if (strcmp($prevRank->get(), $nextRank->get()) >= 0) {
            throw PrevGreaterThanOrEquals::betweenRanks($prevRank, $nextRank);
        }

        [...]
    }

It would be nice to add a check for ! $board->isdownrankable() to broaden the use cases for this plugin. I tried to submit a PR for this myself, but struggle to find a way to get the current board within the rank class without implementing a new parameter to this method.

Do you have any idea for this?