title: Translation in .yml with optional parameter
body: <p>I want to make a translation <code>my_translation</code> with an optional parameter. For example:</p>
  
  <pre><code>&gt; I18n.t('my_translation')
  =&gt; "This is my translation"
  &gt; I18n.t('my_translation', parameter: 1)
  =&gt; "This is my translation with an optional parameter which value is 1"
  </code></pre>
  
  <p>Is this possible?</p>