fix broken link on migration page

Author: jasonrandrews

themes/arm-design-system-hugo-theme/layouts/migration/migration.html

@@ -11,7 +11,7 @@ <h1>Migration overview</h1>
     {{partial "general-formatting/markdown-content-formatting.html" .Params.description}}
     <br>
     <br>    
-    <img src="/migration/Arm-migration-overview.png" alt='Image Alt Text: Arm migration overview' title="Arm Migration Overview" class="content-uploaded-image centered" />
+    <img src="/migration/arm-migration-overview.png" alt='Image Alt Text: Arm migration overview' title="Arm Migration Overview" class="content-uploaded-image centered" />
 
 </div>
 </div>