Refactor documentation

[ajfisher]

As the API has got a bit bigger and there are more examples it is time to refactor the documentation a bit to make it more consumable.

Modifications needed:

[ ] Move all API documentation into their own file
[ ] Update readme to be simple install process and quick example of both backpack and firmata install and run example
[ ] Update example documentation to autobuild somehow
[ ] Create documentation for developers and contribution including how to run tests etc.