Update design-challenge.md

Author: RachHG

content/en/blog/design-challenge.md

@@ -2,7 +2,7 @@
 title: "Help Design Harmony - UX Design Challenge"
 categories: 
   - "development"
-image: "assets/images/Design Challenge Blog Banner.png"
+image: "assets/images/Design_Challenge_Banner.png"
 date: 2025-01-13
 url: "/design-challenge/"
 ---