lib: reword help text for clarity

modified the `-` CLI option help text for
improved readability.

PR-URL: #23016

Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Sakthipriyan Vairamani <thechargingvolcano@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

lib/internal/print_help.js

@@ -140,7 +140,8 @@ function print(stream) {
   const firstColumn = Math.floor(width * 0.4);
   const secondColumn = Math.floor(width * 0.57);
 
-  options.set('-', { helpText: 'script read from stdin (default; ' +
+  options.set('-', { helpText: 'script read from stdin ' +
+                               '(default if no file name is provided, ' +
                                'interactive mode if a tty)' });
   options.set('--', { helpText: 'indicate the end of node options' });
   stream.write(