docs: fix preview port in DOCS_GUIDELINES example (#2903)

Author: santhiprakash

DOCS_GUIDELINES.md

@@ -91,8 +91,7 @@ After CLI commands, show what the user should see:
 
 ```bash
 npx hyperframes preview
-# ✓ Server running at http://localhost:3000
-# ✓ Watching for changes...
+# Studio running at http://localhost:3002
 ```
 
 ### Use CodeGroup for multi-platform commands