src,doc: add doc of --prof flag to help command

Fixes: https://github.com/nodejs/node/issues/16459

PR-URL: https://github.com/nodejs/node/pull/20845
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: Matheus Marchini <matheus@sthima.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

doc/api/cli.md

@@ -240,6 +240,13 @@ resolving relative paths.
 
 See `--preserve-symlinks` for more information.
 
+### `--prof`
+<!-- YAML
+added: v2.0.0
+-->
+
+Generate V8 profiler output.
+
 ### `--prof-process`
 <!-- YAML
 added: v5.2.0

doc/node.1

@@ -149,6 +149,9 @@ Instructs the module loader to preserve symbolic links when resolving and cachin
 .It Fl -preserve-symlinks-main
 Instructs the module loader to preserve symbolic links when resolving and caching the main module.
 .
+.It Fl -prof
+Generate V8 profiler output.
+.
 .It Fl -prof-process
 Process V8 profiler output generated using the V8 option
 .Fl -prof .

src/node.cc

@@ -3234,7 +3234,8 @@ static void PrintHelp() {
          "  --preserve-symlinks-main   preserve symbolic links when resolving\n"
          "                             the main module\n"
 #endif
-         "  --prof-process             process v8 profiler output generated\n"
+         "  --prof                     generate V8 profiler output\n"
+         "  --prof-process             process V8 profiler output generated\n"
          "                             using --prof\n"
          "  --redirect-warnings=file\n"
          "                             write warnings to file instead of\n"