title: Chart.js Subtitle won't display
body: <p>I can't get the subtitle for my pie chart to work. It just won't show.</p>
  
  <p>I was trying this: <a href="https://www.highcharts.com/docs/chart-concepts/title-and-subtitle" rel="noreferrer">https://www.highcharts.com/docs/chart-concepts/title-and-subtitle</a></p>
  
  <pre><code>options: {
      pieceLabel: {
          showZero: true,
          fontColor: '#fff',
          fontFamily: "'Maven Pro', sans-serif",
          position: 'default'
      },
      title: {
          display: true,
          position: 'top',
          text: 'Screened',
          fontSize: 14
      },
      subtitle:{
          text: 'Subtitle',
      },
      legend: {
          display: false
      }
  }
  </code></pre>
  
  <p>My chart displays fine, so I have only shared the options part of the code.</p>
  
  <p>I'm not sure if subtitles are supported by chart.js. If not, suggestions for line break in title or any other substitute are welcome.</p>