My team makes periodical meetings in which we discuss all the cards in the board, one by one. To make meetings faster and more organized we usually add a label titled "done" everytime we finish talking about the card. However, it would be way better if, before each meeting, we could add a label titled "pending" to all the cards in the board so that after discussing each card we could just remove such label. Thus, we need an automation rule or board button to automatically add the label to all the cards in the board but, despite or efforts, we did not figure out how to do it. Can anybody please explain how can I create an automation rule or board button that adds a label to all the cards in the board?