AR Butterflies

- Added a button in the UI to place caterpillars into the scene. Uses cool UI to show where you can place them and at what scale while rotating the caterpillar.
- Added a feature where you can tap anywhere on the screen to summon a butterfly to land where you tapped.
- Updated the UI with 2 new buttons, including the stopwatch button to pause time.
- Updated the instructions slide show to match new features.