Use an input box and button to add new objects to an array callled todos.

Create an HTML list by looping over the array.

Each object should have three properties: id, name and isComplete.

The name property should be displayed in a textbox and be updateable on the keyup event.

Each item should include a checkbox that toggles the isComplete property between true and false.

If the isComplete property is true the whole item should be displayed at 50% opacity.

The array should be saved in and retrieved from localStorage.