[Playtester] "Add counters" customization

{"ops":[{"insert":"Currently, when you right click (or long press) a card, the \"Add counters\" dropdown presents you with a few predetermined options for the most popular counters. Additional counters can be found by clicking \"View all counters\". In a deck that regularly uses one of the more obscure counters, this can be a bit of a hassle. With this proposed feature, we would provide some way for users to dictate which counters appear on that initial \"Add counters\" dropdown.\n\nIf this proposed feature is of interest to you, give the thread a thumbs-up and leave your thoughts below! User interest in each feature will help us prioritize in development.\n"}]}