fix language namespace of diagram editor

Author: fvollmer

docs/extensions/diagrams.md

@@ -1,6 +1,6 @@
 # Diagrams
 
-**Language Namespace :** `de.slisson.mps.editor.diagram`
+**Language Namespace :** `de.itemis.mps.editor.diagram`
 
 If you have downloaded the recent mbeddr master branch, you will have noticed that, for example, component wiring and state machines can now be edited graphically. The screenshots below show examples of these two notations.
 
@@ -27,4 +27,4 @@ To see example code, check out InstanceConfiguration and Statemachine.
 The diagram notation is relatively sophisticated and requires much more documentation than what we can provide right now on this page. More will follow later.
 
 
- 
+