Add CLI demo for cli-demo-generator skill

- Created demos/cli-demo-generator/ directory with animated GIF demo
- Generated demo using auto_generate_demo.py showing basic usage
- Updated README.md to include live demo section for cli-demo-generator
- Demo showcases the skill's ability to create animated CLI demos

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

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

README.md

@@ -348,6 +348,10 @@ Generate professional animated CLI demos and terminal recordings with VHS automa
 - Multiple output formats (GIF, MP4, WebM)
 - VHS tape file templates
 
+**🎬 Live Demo**
+
+![CLI Demo Generator Demo](./demos/cli-demo-generator/generate-demo.gif)
+
 ---
 
 ## 🎬 Interactive Demo Gallery