Update functional/stateful-types.md

Author: simonsan

functional/stateful-types.md

@@ -239,7 +239,7 @@ There are a number of simpler state machines, however, that have their own patte
 
 1. If the state transition is during construction/finalizing of an object, see
 [Builder Pattern](../patterns/creational/builder.md).
-1. If the state transitions don't change invariants much, see [Strategy Pattern](../patterns/behavioural/strategy.md).
+2. If the state transitions don't change invariants much, see [Strategy Pattern](../patterns/behavioural/strategy.md).
 
 ## See also