The idea is to paste a list of line-separated items into a subtask, which (upon pressing enter or return) will then create subtasks for each of the items. Both Trello and Wunderlist do this.
From the above page:
"You can easily import items from a list (or a spreadsheet) to a checklist as long as each item is on a separate line. Copy the list items and paste them in to the "Add item" field in your checklist and press 'enter.' A separate checklist item will be created for each listed item."
The idea is to paste a list of line-separated items into a subtask, which (upon pressing enter or return) will then create subtasks for each of the items. Both Trello and Wunderlist do this.
See 'Importing Checklist Items' on this article: https://help.trello.com/article/737-adding-checklists-to-cards
From the above page:
"You can easily import items from a list (or a spreadsheet) to a checklist as long as each item is on a separate line. Copy the list items and paste them in to the "Add item" field in your checklist and press 'enter.' A separate checklist item will be created for each listed item."