[Docs] need to explain when to use Akka.Streams.RabbitMQ vs Akka.Streams.AMQP

[Aaronontheweb]

Please describe what you are trying to understand
It's not clear to me, a RabbitMQ / AMQP novice, which of these two libraries I should be using and why.

[Aaronontheweb]

We need to add this to the Alpakka docs but also probably in the README for the directory these two are located in

[Aaronontheweb]

#38 - is Rabbit still AMQP 1.0 incompatible?

[Aaronontheweb]

Looks like that's the case: https://www.rabbitmq.com/specification.html

RabbitMQ implements version 0-9-1 of the AMQP specification in the core, with a number of extensions to the specification.

RabbitMQ implements AMQP 1.0 via a plugin. However, AMQP 1.0 is a completely different protocol than AMQP 0-9-1 and hence not a suitable replacement for the latter. RabbitMQ will therefore continue to support AMQP 0-9-1 indefinitely.

The 0-9-1 (with and without extensions) specifications are linked to below for your convenience. We recommend reading them if you want to learn more about AMQP 0-9-1. Please see our AMQP 0-9-1 Overview guide, AMQP 0-9-1 Reference guide, and the rest of documentation for more information.