title: autotable not found in jsPDF
body: <p>i have the same problem since.
  1. installed jsPDF and jspdf-autotable with
     npm install jspdf
     npm install --save @types/jspdf
     npm install jspdf-autotable --save</p>
  
  <ol start="2">
  <li>Import jspdf into app.component.ts with
    import * as jsPDF from 'jspdf';
    import 'jspdf-autotable';</li>
  <li>this is my method.ts</li>
  </ol>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>generatedile(){
            var columns = [
              {title: "ID", dataKey: "id"},
              {title: "Name", dataKey: "name"}, 
              {title: "Country", dataKey: "country"},
          ];
          var rows = [
              {"id": 1, "name": "Shaw", "country": "Tanzania"},
              {"id": 2, "name": "Nelson", "country": "Kazakhstan"},
              {"id": 3, "name": "Garcia", "country": "Madagascar"},
          ];
           
          // Only pt supported (not mm or in)
          var doc = new jsPDF('p', 'pt');
          doc.autoTable(columns, rows, {
              styles: {fillColor: [100, 255, 255]},
              columnStyles: {
                id: {fillColor: 255}
              },
              margin: {top: 60},
              addPageContent: function(data) {
                doc.text("Header", 40, 30);
              }
          });
          doc.save('table.pdf');
  }</code></pre>
  </div>
  </div>
  </p>