Document PM2 configuration and remove unnecessary ready signal

- Added PM2 configuration notes to README
- Documented that wait_ready is false by default (no signals needed)
- Provided advanced usage instructions for users who need wait_ready
- Removed unnecessary process.send('ready') from simple-website example

This ensures users understand the default PM2 behavior and know how
to customize it if needed.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

examples/simple-website/server.js

@@ -26,8 +26,4 @@ app.get('/ping', (req, res) => {
 
 app.listen(port, () => {
   console.log(`Simple website running on port ${port}`);
-  // Send ready signal to PM2
-  if (process.send) {
-    process.send('ready');
-  }
 });