Multiple Tours, Enhanced Backdrop, Hotkeys
Added or enhanced the following features:
- Updated the documentation with missing or inacurate information and best practices
- Created a better "backdrop" the allows interaction with the content of the target element
- Added the "scrollIntoView" options that configures whether or not the tour scrolls after a step is shown
- Merged @diego-vieira's PR that adds the "useHotkeys" option, allowing the tour to be controlled with the keyboard
- Added UI Router integration
- Multiple tours