Quickstart in book does not provide a working example

[jlgerber]

It is painful to get started with Juniper due to the lack of a complete working example. The quickstart should provide a simple working example that compiles and runs out of the box.

It would be really helpful to pick a server framework and provide a working example in the book, instead of referring to external examples. I would point out that there are a number of examples spread throughout the codebase, and none of them really address the beginner.

A couple of other observations:

• mutations are not covered in enough depth.
• the lack of a rust client is conspicuously absent