Update Message Oriented Middleware Docs

[weberjm]

In docs/Services/MessageOrientedMiddleware.md, line 42 references an image called "Assets/MessageOrientedMiddleware.png." This file does not exist, nor does any similarly named image appear to exist in the assets/ folder. Please remove the image or provide the referenced asset in the proper location, and update the reference.

[RobinBrinkmann]

I removed the image as well as the description. The documentation of this service is very minimal now and should be updated / expanded.