Update doc/specs/stdlib_hashmaps.md

Co-authored-by: Jeremie Vandenplas <jeremie.vandenplas@gmail.com>

Author: wclodius2

doc/specs/stdlib_hashmaps.md

@@ -1287,7 +1287,7 @@ Procedures to modify the content of a map:
 
 Procedures to report the content of a map:
 
-* `map 5 get_other_data( key, other, exists )` - Returns the other data
+* `map % get_other_data( key, other, exists )` - Returns the other data
   associated with the `key`;
 
 * `map % key_test( key, present)` - Returns a flag indicating whether