Add "For example,"

Author: camelid

compiler/rustc_error_codes/src/error_codes/E0607.md

@@ -14,9 +14,9 @@ address.
 
 Fat pointers are pointers referencing Dynamically Sized Types (also called
 DSTs). DSTs don't have a statically known size, therefore they can only exist
-behind some kind of pointer that contains additional information. Slices and
-trait objects are DSTs. In the case of slices, the additional information the
-fat pointer holds is their size.
+behind some kind of pointer that contains additional information. For example,
+slices and trait objects are DSTs. In the case of slices, the additional
+information the fat pointer holds is their size.
 
 To fix this error, don't try to cast directly between thin and fat pointers.