fix: fixing incorrect comma placement

Author: jordanvn

docs/src/pages/[platform]/theming/icons/react.mdx

@@ -88,14 +88,14 @@ const icons = {
   stepperField: {
     add: () => </>,
     remove: () => </>,
-  }
+  },
   storageManager: {
     upload: () => </>,
     remove: () => </>,
     error: () => </>,
     success: () => </>,
     file: () => </>,
-  },
+  }
 }
 ```
 </ExampleCode>