Add reminder about what the editor is

Author: SteveBarnett

sites/en/intro-to-rails/setting_the_default_page.step

@@ -14,7 +14,7 @@ goals {
 steps {
 
   step "Add a root route" do
-    message "Open the file `config/routes.rb` in an editor."
+    message "Open the file `config/routes.rb` in an editor (In the InstallFest yesterday, we suggested that you install and use **Sublime Text** as your editor)."
 
     message "Search the file for **root**, it should be near the top if you are using Rails 4."