Accessibility: visually impaired users unable to check on the existing task list

Test Environment:

1. Confluence 6.7.0
2. Firefox 57.04 , Chrome 64
3. Windows 10 Pro with NVDA

Steps to Reproduce:

1. In Windows, Use NVDA Screen Reader
2. Create a new page
3. Insert a new task
4. Save the page
5. Mouse over the task

Expected Behaviour
Confluence will have audio whenever cursor is on the task

Actual Behaviour
Task is not detected and user will not be able to tell if there is task present in the line