Add task editing

**Description:**

- Click on a task's description to turn it into an editable field.
- Click on a task's due date to turn it into an editable field.
- Clicking off of either element turns it back into its original form.

Start by locating the JavaScript UI code that renders a task's description and due date. Trace how each field is displayed and how clicks outside editable elements are handled. Done means both fields can be edited by clicking them and return to their original display form when focus moves away.

Written by the indexing model from the issue text.