doc: add --experimental-top-level-await to man page

PR-URL: #33529
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Zeyu Yang <himself65@outlook.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>

doc/node.1

@@ -143,6 +143,9 @@ keyword support in REPL.
 .It Fl -experimental-specifier-resolution
 Select extension resolution algorithm for ES Modules; either 'explicit' (default) or 'node'
 .
+.It Fl -experimental-top-level-await
+Enable experimental top-level await support in ES modules.
+.
 .It Fl -experimental-vm-modules
 Enable experimental ES module support in VM module.
 .