Taking notes on our own cards

[philipqlu]

While playing, sometimes we can deduce what value a card is based on implicit hints and non-hints.

Eg. We draw a card that isn't immediately playable, with hint tokens to give. The lack of a hint after we draw this card can give us information that the game's UI doesn't show (understanding that when we receive hints, colors/numbers are automatically crossed out for us).

It would be nice to have a way of writing notes on our cards, so we can better track these clues throughout the game.