Icon Request - Inverse of arrows-expand (arrows-contract?)

[robertrbairdii]

There's currently the arrows-expand icon, it'd be really nice to have the opposite version with the arrows pointing inward.

As an example use case, we're using the arrows-expand icon on a button to make our application go full screen, we'd likely use an icon with inward facing arrows on our exit fullscreen mode button.

[viniciussbs]

Same here. I'm building a modal window that can be full screen (not native full screen, but full viewport).

[ecklf]

@sschoger quickly made the suggested files for you. I also did notice a mistake that is addressed in #117 and also fixed that for those new icons.