Orientation and Devices Sizes

[basequatro]

Would be great to have support for orientation, and more examples for screen sizes.

[ColeTownsend]

It seems like there is stuff for orientation https://github.com/aybadb/react-native-responsive#todos. For another example check out what I added in a PR to the readme https://github.com/aybadb/react-native-responsive/pull/4/files