Added function documentation

examples/UsageExamples.py

@@ -3,7 +3,8 @@
 
 from fastkml import kml
 
-def print_child_features(element):    
+def print_child_features(element):
+    """ Prints the name of every child node of the given element, recursively """
     if not getattr(element, 'features', None):
         return
     for feature in element.features():
@@ -19,4 +20,4 @@ if __name__ == '__main__':
     with open(fname) as kmlFile:
         k.from_string(kmlFile.read())    
 
-    print_child_features(k)
\ No newline at end of file
+    print_child_features(k)