add platforms to index page (#7617)

Co-authored-by: katiegoines <[email protected]>

Author: katieklein

src/pages/[platform]/build-a-backend/troubleshooting/index.mdx

@@ -11,7 +11,10 @@ export const meta = {
     'nextjs',
     'react',
     'react-native',
-    'vue'
+    'vue',
+    'swift',
+    'android',
+    'flutter'
   ]
 };