Add example project

[LucianBuzzo]

Many frameworks provide an example site, showing simple use cases for running it. We should take inspiration from express-graphql ( https://github.com/graphql/express-graphql/tree/master/examples ) and add a examples folder in this project.

[zwhitchcox]

I created an example project on my personal github (https://github.com/zwhitchcox/ref-pinejs) just following the getting started, which I also updated in #447.