Update video thumbnail and title in README

Author: pH-7

README.md

@@ -6,7 +6,7 @@ A beautiful, gamified Flutter app for learning AI and Data Science from beginner
 ![Flutter](https://img.shields.io/badge/Flutter-3.0+-blue)
 ![License](https://img.shields.io/badge/license-MIT-green)
 
-[![Video: Write clean code as a software engineer. One Thing Principle](https://i1.ytimg.com/vi/9rgu1VQy_Ks/sddefault.jpg)](https://www.youtube.com/watch?v=9rgu1VQy_Ks)
+[![AI Data Science Learning App](https://i1.ytimg.com/vi/9rgu1VQy_Ks/sddefault.jpg)](https://www.youtube.com/watch?v=9rgu1VQy_Ks)
 
 **[Click here to watch the full video on YouTube  →](https://www.youtube.com/watch?v=9rgu1VQy_Ks)**