Plug functions have the following signature
(Plug.Conn.t, Plug.opts) :: Plug.Conn.t
passing the connection to a “main” function plug for the route, and specifying the behavior with an atom in Plug.opts. If the behavior needs additional configuration or to be passed through other different plugs, I could make a Behavior.Plug with Plug.Builder, and forward the connection to that plug.
