Document available options

I'm having difficulty figuring out how all the middleware and options work together.

There are three middleware: `wrap-access-rules`, `wrap-authentication`, `wrap-authorization`. How do these work together and which are necessary? It seems like if I use `wrap-access-rules`, I may omit `wrap-authorization`.

What options are available for backends? I see `:unauthorized-handler`, does a `:unauthenticated-handler` exist?
What options are available for `wrap-access-rules`? I see `:rules` and `:on-error`. Does/should `:on-error` handle unauthenticated requests? Unauthorized requests? When should `:on-error` be used instead of the `:unauthorized-handler` option specified in the backend?

These concerns should be better documented.