Fixed typo in docs/topics/cache.txt.
@@ -906,7 +906,7 @@ from the cache, not just the keys set by your application. ::
You can also increment or decrement a key that already exists using the
``incr()`` or ``decr()`` methods, respectively. By default, the existing cache
-value will incremented or decremented by 1. Other increment/decrement values
+value will be incremented or decremented by 1. Other increment/decrement values
can be specified by providing an argument to the increment/decrement call. A
ValueError will be raised if you attempt to increment or decrement a
nonexistent cache key.::
