Fix Exception.md example type error (#212)

* Fix Exception.md example type error

* Update exception.md

Author: bobbypriam

src/pages/guide/language/exception.md

@@ -17,10 +17,12 @@ let getItem theList => {
 };
 
 let result = try (getItem [1, 2, 3]) {
-| Not_found => print_endline "Item not found!"
+| Not_found => 0 /* Default value if getItem throws */
 };
 ```
 
+Note that the above is just for demonstration purposes; in reality, you'd return an `option int` directly from `getItem` and avoid the `try` altogether.
+
 You can directly match on exceptions _while_ getting another return value from a function:
 
 ```reason