Clarify the situation

Author: paf31

src/Data/Array/Unsafe.purs

@@ -1,7 +1,7 @@
 -- | Unsafe helper functions for working with immutable arrays.
 -- | 
 -- | _Note_: these functions should be used with care, and may result in unspecified
--- | behavior.
+-- | behavior, including runtime exceptions.
 
 module Data.Array.Unsafe where