feature: wrap each todo in its own todo item controller, and created an isCompleted property in this controller
feature: update the script tag to referance a todo (item) controller
comment: explain what the controller is doing and the reference to the template
feature: todo itemController, that implements the isCompleted property
feature: automatically update the number of todos left using computed properties on the todos controller
feature: add a remaining property that computes the remaining todos left based on the @each.isCompleted property
feature: add an inflection property that determines whether to pluralize or singularize the words based on how many todods remaining