chore(ui): add more info to table footer (#7788)
### Description
Add explanation to the table footer of how to interact with tasks.
### Testing Instructions
<img width="1118" alt="Screenshot 2024-03-20 at 1 26 04 PM"
src="https://github.com/vercel/turbo/assets/4131117/e0b9f632-61f4-4bdf-a79b-ece4c0d0f2eb">
Closes TURBO-2664
