first commit of api spec

This isn’t how I understood the function of `GET` requests for a court. Because of the way we send data to the content store, we may not have stored the full representation of the court, so we might well only be able to return information about when we last published the court and the current public URL, for example.

I’m tempted to suggest we leave out details about the response format for now, and deal with this when we get to it. I think this is mostly going to be for internal debugging anyway, so it’s not going to hold us up at the moment.