Feature Request: Bulk delete all cards in a topic

[maodoanminnh]

Currently, we have to manually delete a card, which can take a bit long if there are a few hundred of them in a topic. It'd be great if we can delete a topic and all the cards it contains, not move them to the unassigned topic as it does now.

Your app is so good, my students find it very helpful. I'm just putting forward some ideas that I think can make it even better. Thank you very much.