Add 'method', fixes compilation error

Author: coke

doc/Type/Metamodel/MROBasedMethodDispatch.pod6

@@ -42,7 +42,7 @@ self.SomeParentClass::the_method();
 
 =head2 method can
 
-    can($obj, $name)
+    method can($obj, $name)
 
 Returns the list of methods of that name the object can do.