More GraphQL language feature examples

[acao]

It would be grand to add more examples to the schema of new features we have. That way, we can fully demonstrate the features of GraphiQL, etc to newcomers!

high priority:

• fields with resolvers that yield after a delay, for demoing @defer/@stream

all else:

• unions
• interfaces implementing interfaces
• custom directives and scalars maybe? demoing new directive introspection features would be nice
• subscriptions - how to do this with netlify functions though? possible with aws in a complicated way... would be cool to have a subscription field that provides realtime starship coordinates

[acao]

@n1ru4l would you like to add to this schema some fields that make it easier to demo defer/streamed content? obviously we can defer or stream any field, but using generators with setTimeout(), it seems we can amplify the visual effect

[n1ru4l]

@acao I will try to take a look this weekend!