WIP Add admin settings pages, reserved username config

Prototyping settings forms

config/routes.rb

@@ -43,6 +43,11 @@ Rails.application.routes.draw do
     get 'invitations', to: 'invitations#index'
     resources :donations
     get 'lightning', to: 'lightning#index'
+
+    namespace :settings do
+      resources 'registrations', only: ['index', 'update']
+      resources 'services', only: ['index', 'update']
+    end
   end
 
   authenticate :user, ->(user) { user.is_admin? } do