UX: Move site settings under its own tab.

https://meta.discourse.org/t/chatroom-integration-plugin-discourse-chat-integration/66522/88

config/locales/client.en.yml

@@ -1,5 +1,9 @@
 en:
   js:
+    admin:
+      site_settings:
+        categories:
+          chat_integration: "Chat Integrations"
     chat_integration:
       menu_title: "Chat Integrations"
       settings: "Settings"
@@ -201,4 +205,3 @@ en:
             flow_token:
               title: "Flow Token"
               help: "The flow token provided after creating a source for a flow into which you want to send messages."
-

config/settings.yml

@@ -1,4 +1,4 @@
-plugins:
+chat_integration:
   chat_integration_enabled:
     default: false
   chat_integration_discourse_username: