Note/Exercise label works for long titles

This can wait and get reviewed/tested/merged **after** Monday.

Tested all 12 permutations of:

- `.note`, `.exercise`
- `.ui-has-child-title` and `:not(.ui-has-child-title)`
- `:not([data-label])`, `:[data-label=""]`, and `:[data-label != ""]`

I assumed exercises would be the same as examples since they use the same CSS.