Added the code for lesson 2
Completed version of lesson 2 with all tasks implemented
Overview slide and first concept slide for AngularJS lesson 2
Add an input element bound to the model
Tidied up the formatting
Format code example correctly
Slide for changing the state of elements
Final slides for AngularJS lesson 2
Comment out code for lesson 2
Merge branch 'lesson_2'

Merging in the AngularJS bits for lesson 2.
Merging because of changes to the shared slide index.html page.