Checklists: item hierarchy via indentation or other means (Parent-Child items)

Checklists: item hierarchy via indentation or other means (Parent-Child items)

Hello George, happy new year!!!!
I was thinking that indentation or other means to introduce organized subsets in the checklists would be very useful. Currently I have a capitalized and underlined title followed by a colon to specify that the following points refer to the specific headline.