Update README.md with plantuml GFM test.

README.md

@@ -32,6 +32,14 @@ Of course the gitlab-CI Integration requires a gitlab-server.
 ### Required Tools
 doxygen, sphinx, PlantUML, cmake, SWIG
 
+If you don't know PlantUML, here's an example in Gitlab markdown:
+```plantuml
+Bob -> Alice : hello
+Alice -> Bob : hi
+```
+and another one you can find in 
+
+
 ### Documentation
 The documentation is generated under the doc and generates nice Sphinx output that is proper html and can be served
 by any webserver.