feat: update initializer

lib/install/create_initializer.rb

@@ -2,10 +2,20 @@
 create_file Rails.root.join("config/initializers/turbo_train.rb") do
   %{
 Turbo::Train.configure do |config|
-  config.mercure_domain = 'localhost'
-  config.publisher_key = 'testing'
-  config.subscriber_key = 'test'
   config.skip_ssl_verification = true # Development only; don't do this in production
+  config.default_server =  # Default value is :mercure
+
+  config.server :mercure do |mercure|
+    mercure.mercure_domain = 'localhost'
+    mercure.publisher_key = 'testing'
+    mercure.subscriber_key = 'test'
+  end
+
+  config.server :fanout do |fanout|
+    fanout.service_url = ''
+    fanout.service_id = ''
+    fanout.fastly_key = ''
+  end
 end
   }
 end