fix typo

Author: performantdata

_sips/sips/2014-06-27-42.type.md

@@ -448,7 +448,7 @@ applications which work with large datasets.
   ```
   final val narrow = 23      // inferred type of narrow: 23
 
-  class Widen
+  class Wide
   object Narrow extends Wide
   def id[T](t: T): T = t
   id(Narrow)                 // result is Narrow: Narrow.type