Add a cookbook with examples showing how to write various real-world resources

[malcolmsparks]

I think it's easier for beginners to copy-and-paste from examples than learn all of the Liberator possibilities firsthand.

[fractastical]

Not sure how you'd want to do this, but interested in contributing. Maybe just link another github repo or two that has simple examples of complete apps showing how to implement certain behaviors (i.e. creating resources on the fly, nesting resources, etc.)

[ordnungswidrig]

This is partially addressed by the new documentation and tutorial. Nevertheless we need a set of examples in the source tree to "quick start" developers. Thus I leave this one open for now.

[prachetasp]

This is closed since /examples now exists right?