chore: update readme with codeblock.dev intro video

Author: hamed-shirbandi

README.md

@@ -3,8 +3,8 @@
 A comprehensive SaaS application template built with the [CodeBlock Dev Kit](https://codeblock.dev). This template provides a complete foundation for building modern, scalable SaaS applications with enterprise-grade architecture.
 
 <div align="center">
-  <a href="https://www.youtube.com/embed/dQw4w9WgXcQ" target="_blank">
-    <img src="https://img.youtube.com/vi/dQw4w9WgXcQ/maxresdefault.jpg" alt="CodeBlock Dev Kit Template Demo" width="560" height="315" style="border-radius: 8px; box-shadow: 0 4px 8px rgba(0,0,0,0.1);">
+  <a href="https://www.youtube.com/embed/pkg5zMn2a6A" target="_blank">
+    <img src="https://codeblock.dev/images/intro.png" alt="CodeBlock Dev Kit Template Demo" width="560" height="315" style="border-radius: 8px; box-shadow: 0 4px 8px rgba(0,0,0,0.1);">
   </a>
 </div>