debugger: add usage example for --port

PR-URL: #38400
Backport-PR-URL: #39446
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: RafaelGSS

lib/internal/inspector/_inspect.js

@@ -340,6 +340,7 @@ function startInspect(argv = process.argv.slice(2),
 
     console.error(`Usage: ${invokedAs} script.js`);
     console.error(`       ${invokedAs} <host>:<port>`);
+    console.error(`       ${invokedAs} --port=<port>`);
     console.error(`       ${invokedAs} -p <pid>`);
     process.exit(1);
   }

test/parallel/test-debug-usage.js

@@ -11,7 +11,7 @@ child.stderr.setEncoding('utf8');
 
 const expectedLines = [
   /^\(node:\d+\) \[DEP0068\] DeprecationWarning:/,
-  /Usage: .*node.* debug script\.js\r?\n       .*node.* debug <host>:<port>\r?\n       .*node.* debug -p <pid>\r?\n$/,
+  /Usage: .*node.* debug script\.js\r?\n       .*node.* debug <host>:<port>\r?\n       .*node.* debug --port=<port>\r?\n       .*node.* debug -p <pid>\r?\n$/,
 ];
 
 let actualUsageMessage = '';