Add a generator for draper decoration gem
user
```ruby
require "rails/generators"

module Suspenders
  class DraperGenerator < Rails::Generators::Base
    source_root File.expand_path(
      File.join("..", "..", "..", "templates"),
      File.dirname(__FILE__),
    )

    def add_factory_bot
      gem "draper"
      Bundler.with_clean_env { run "bundle install" }
    end

    def configure_draper
      bundle_command "exec rails generate draper:install"
    end
  end
end
```
assistant