Update example in contramap (evilsoft#449)

in the docs the property num had the same type as the example above.
the change makes clear the contramap is not working on a different property instead of the type

docs/src/pages/docs/crocks/Arrow.md

@@ -292,7 +292,7 @@ arrAdd10Value
 //=> 10
 
 arrAdd10Value
-  .runWith({ num: '23' })
+  .runWith({ num: 23 })
 //=> 10
 ```