Fixed #20476 -- Typo.

docs/ref/class-based-views/index.txt

@@ -32,7 +32,7 @@ A class-based view is deployed into a URL pattern using the
 .. admonition:: Thread safety with view arguments
 
     Arguments passed to a view are shared between every instance of a view.
-    This means that you shoudn't use a list, dictionary, or any other
+    This means that you shouldn't use a list, dictionary, or any other
     mutable object as an argument to a view. If you do and the shared object
     is modified, the actions of one user visiting your view could have an
     effect on subsequent users visiting the same view.