[markdown] Automatic lists should not add additional completed tasks
Based on feedback in !81079 (comment 859300255)
When adding a new task list item to a list, if the current task item is marked done, [x]
, then the new one is automatically marked done.
- [x] a completed task
- [x]
Instead, always create new, uncompleted task
- [x] a completed task
- [ ]
Also, recognize [X]
as a valid task item, like other task handling does