title: how to add a title to my ng2-charts bar chart
body: <p>I have a bar chart with below code...works brilliantly....except its missing a title.</p>
  
  <p>Does ng2-charts have a title option in API? eg 'sales chart'.
  The values are pulled from the typescript file.</p>
  
  <pre><code>&lt;div&gt;
    &lt;div style="display: block"&gt;
      &lt;canvas baseChart
              [datasets]="barChartData"
              [labels]="barChartLabels"
              [options]="barChartOptions"
              [legend]="barChartLegend"
              [chartType]="barChartType"
              (chartHover)="chartHovered($event)"
              (chartClick)="chartClicked($event)"&gt;&lt;/canvas&gt;
    &lt;/div&gt;
  </code></pre>
  
  <p></p>