fix(docs): scan ruby ui gem classes in tailwind

Author: djalmaaraujo

docs/app/assets/stylesheets/application.tailwind.css

@@ -3,6 +3,8 @@
 @plugin "@tailwindcss/forms";
 @plugin "@tailwindcss/typography";
 
+@source "../../../../gem/lib/ruby_ui";
+
 /* Safelist classes from RubyUI gem components rendered by the docs app. */
 @source inline("dark:inline-block");