1  - `past_gap`: if a sibling of a new card has been reviewed in the past `past_gap` days, the new card is skipped for today (buried).
2  - `future_gap`: if a sibling of a new card is due in the next `future_gap` days, the new card is skipped for today (buried).
3  - `verbose`: if set, when a card is skipped a tooltip appears and a log line is printed to the console, indicating the id of the card buried.