Nested Todos App

Let's see how to use it...

Add todo: (1) type the task into the text box. (2) click the 'Add' button or press the 'Enter' key.
Delete todo: click the 'x' button.
Add sub todo: (1) click the '+' button. (2) type the task into the pop up text box. (3) click the 'Save' button or press the 'Enter' key.
Edit an existing todo: (1) double click the task name. (2) change the content. (3) click the 'Save' button or press the 'Enter' key.
Mark todo as complete: click the square box in front of the todo.

This is an execise created by Jason Liao for the Watch and Code premium course