Update src/stdlib_sorting.fypp

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

Author: wclodius2

src/stdlib_sorting.fypp

@@ -128,10 +128,10 @@ module stdlib_sorting
                                log(1.6180339887_dp) ) )
 
     type run_type
-! Version: experimental
-!
-! Used to pass state around in a stack among helper functions for the
-! `ORD_SORT` and `SORT_INDEX` algorithms
+!! Version: experimental
+!!
+!! Used to pass state around in a stack among helper functions for the
+!! `ORD_SORT` and `SORT_INDEX` algorithms
         integer(int_size) :: base = 0
         integer(int_size) :: len = 0
     end type run_type