Update doc/specs/stdlib_logger.md

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

Author: milancurcic

doc/specs/stdlib_logger.md

@@ -176,15 +176,15 @@ an `intent(in)` argument. It shall be the name of the file to be opened.
 ```fortran
 program demo_global_logger
     use stdlib_logger, global => global_logger
-    ...
+
     integer :: unit, stat
-    ...
+
     call global % add_log_file( 'error_log.txt', unit, &
         position='asis', stat=stat )
     if ( stat /= success ) then
          error stop 'Unable to open "error_log.txt".'
     end if
-     ...
+
 end program demo_global_logger
 ```