title: Radio button with title and subtitle label
body: <p>I have 3 radio buttons that look like buttons.</p>
  
  <p><a href="https://plnkr.co/edit/sNJCB6yKt31Et7bQrKKO?p=preview" rel="nofollow noreferrer"><strong>Here</strong></a> the code:</p>
  
  <pre><code>&lt;div id='vaccine-selector-container' class="switch-field"&gt;
          &lt;span class='custom-control custom-radio custom-control-inline'&gt;
              &lt;input type='radio' id='rb-dtp' name='vaccine-selector' class='custom-control-input' value='DTP' autocomplete='off' checked&gt;
              &lt;label class='custom-control-label' for='rb-dtp'&gt;DTP&lt;/label&gt;
              &lt;label class='custom-control-label-help' for='rb-dtp'&gt;Vaccine against diphtheria, tetanus, pertussis&lt;/label&gt;
          &lt;/span&gt;
          &lt;span class='custom-control custom-radio custom-control-inline'&gt;
              &lt;input type='radio' id='rb-mmr' name='vaccine-selector' class='custom-control-input' value='MMR' autocomplete='off'&gt;
              &lt;label class='custom-control-label' for='rb-mmr'&gt;MMR&lt;/label&gt;
              &lt;label class='custom-control-label-help' for='rb-mmr'&gt;Vaccine against measles, mumps and rubella&lt;/label&gt;
          &lt;/span&gt;     
          &lt;span class='custom-control custom-radio custom-control-inline'&gt;
              &lt;input type='radio' id='rb-pol' name='vaccine-selector' class='custom-control-input' value='POL' autocomplete='off'&gt;
              &lt;label class='custom-control-label' for='rb-pol'&gt;POL&lt;/label&gt;
              &lt;label class='custom-control-labelHelp' for='rb-pol'&gt;Vaccine against poliomyelitis&lt;/label&gt;
          &lt;/span&gt;
      &lt;/div&gt;
  </code></pre>
  
  <p>But what I want is this: a "title" label and a "subtitle" label.</p>
  
  <p><a href="https://i.stack.imgur.com/mhj0X.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/mhj0X.png" alt="enter image description here"></a></p>
  
  <p>How can I do?</p>