update changes.rst

CHANGES.rst

@@ -5,8 +5,13 @@ Changes
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 - compatibility for python 3
-- reimplement ``zope.interface.implements`` with a grokker
-  for both python2 and python3
+- Python 3 doesn't support the directive ``zope.interface.implements``
+  any more and is required to use the ``@implementer`` class decorator instead.
+  This version of grokcore.components provides its own 
+  ``grokcore.component.implements`` directive for both Python 2 and 3.
+  So this directive can still be used with the help of a grokker.
+  If you use grokcore.components >= 2.6  the new implementation will be used
+  while earlier versions used zope.interface.implements.  
 
 2.5 (2012-05-01)
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