title: Make Contact form 7 Add custom required checkbox
body: <p>I want to use custom styled checkbox and checkmark with Contact form 7 plugin, but "required" html attribute doesn't seem to work with this plugin.</p>
  
  <p>My code looks like this at the moment:</p>
  
  <pre><code>&lt;input class="form__checkbox-input" type="checkbox" name="privaatsuspoliitika" id="the-terms" required&gt;
  </code></pre>
  
  <p>Is it possible to make it required without using acceptance checkbox/default checkbox? I don't want plugin to generate checkbox html for me since it also adds span and label tags (it makes my custom checkbox not work) and I don't think there is an option to just add input with type of checkbox :/.</p>