Fixed issue with manifest.json route

• Fixed:
- issue with manifest.json route, now returning hardcoded json successfully

app/controllers/manifests_controller.rb

@@ -1,9 +1,30 @@
 # frozen_string_literal: true
 
 class ManifestsController < EmptyController
-
   def show
-    render json: InstancePresenter.new, serializer: ManifestSerializer
+    render json: {
+      name: 'Gab Social',
+      short_name: 'Gab Social',
+      description: 'Gab is a social network that champions free speech, individual liberty and the free flow of information online. All are welcome.',
+      icons: [{
+        src: '/android-chrome-192x192.png',
+        sizes: '192x192',
+        type: 'image/png',
+      }],
+      theme_color: '#21D07B',
+      background_color: '#191b22',
+      display: 'standalone',
+      start_url: '/home',
+      scope: root_url,
+      share_target: {
+        action: '/compose',
+        method: 'GET',
+        params: {
+          title: 'title',
+          text: 'text',
+          url: 'url',
+        }
+      }
+    }
   end
-
 end