Update doc/specs/stdlib_hashmaps.md

Co-authored-by: Jeremie Vandenplas <[email protected]>

Author: chuckyvt

doc/specs/stdlib_hashmaps.md

@@ -752,7 +752,7 @@ is an `intent(out)` argument.
 is an `intent(out)` argument.
 
 `value`: if the first argument is `key`, `value` shall be a default
-`character` string scalar expression, or a vector expression of type integer
+`character` string scalar expression, or a vector expression of type `integer`
 and kind `int8` or `int32`, while for a first argument of type 
 `other` `value` shall be of type `class(*)`. It is an `intent(in)` 
 argument.