Clarify how to send 'opts' when not using client.connect

[MarcoWorms]

Since you don't need to use client.connect to be able to use the client's methods, we need to add better documentation to that part so people can make simple calls without using connect if they want to. Even though client.connect will always be better for anything that needs more than 1 request, I think we can give a much better dev experience by documenting and pointing out how to easily use the methods without the partial application of the authentication strategy.

[MarcoWorms]

@guarilha how do you think we can achieve this?