docs: update README image path to bypass cache

Author: coderanik

README.md

@@ -115,7 +115,7 @@ Released under the [MIT License](LICENSE) — free to use, modify, and distribut
 ## 🎨 UI Design
 
 <div align="center">
-  <img src="assets/ui_design.png" width="600" alt="BraveQR UI Design" />
+  <img src="assets/braveqr_preview.png" width="600" alt="BraveQR UI Design" />
 </div>
 
 ---