title: Rails admin navigation_label translation
body: <p>I'm localizing Rails app with Rails Admin using I18n. In some models (<code>Good &lt; ActiveRecord</code>) Rails admin configured as follows:</p>
  
  <pre><code>rails_admin do
    label = 'Good'
    label_plural = 'Goods'
    navigation_label = 'Settings'
    navigation_icon = 'icon-settings'
  end
  </code></pre>
  
  <p>I know that <code>label</code> localization can be stored in <code>config/locales/en.yml</code> (Translations for Active Record Models) as follows:</p>
  
  <pre><code>en:
    activerecord:
      models:
        good:
          one: Good
          few: Goods
          many: Goods
          other: Goods
  </code></pre>
  
  <p>The question is: how can I store and use locale for navigation_label? (Can't find the answer on rails admin wiki page)</p>