Added a description to TrafficLight generator

boxes/generators/trafficlight.py

@@ -37,6 +37,9 @@ class ShadyEdge(edges.BaseEdge):
 
 class TrafficLight(Boxes): # change class name here and below
     """Traffic light"""
+    description = """The traffic light was created to visualize the status of a Icinga monitored system.
+
+When turned by 90°, it can be also used to create a bottle holder."""
     
     def __init__(self):
         Boxes.__init__(self)