Replace Flutter SDK icon temporarily with a more relevant one

Author: dhananjayj-dev

fern/docs/pages/developer-intro.mdx

@@ -64,7 +64,7 @@ Numerous snap-ins are available on the DevRev [Marketplace](https://devrev.ai/ma
 
   <Card
     title="DevRev SDK for Flutter"
-    icon="fa-brands fa-flutter"
+    icon="fa-regular fa-code"
     href="/sdks/mobile/flutter/quickstart"
     />
 </Cards>

fern/docs/pages/sdks/index.mdx

@@ -35,7 +35,7 @@ The DevRev SDK is a powerful tool designed to further enhance our widget on your
 
   <Card
     title="DevRev SDK for Flutter"
-    icon="fa-brands fa-flutter"
+    icon="fa-regular fa-code"
     href="/sdks/mobile/flutter/quickstart"
     />
 

fern/versions/public.yml

@@ -172,7 +172,7 @@ navigation:
             path: ../docs/pages/sdks/mobile/cordova/troubleshooting.mdx
       - section: DevRev SDK for Flutter
         slug: flutter
-        icon: fa-brands fa-flutter
+        icon: fa-regular fa-code
         contents:
           - page: Quickstart guide
             slug: quickstart