message: renamed multi to combo chart
diff: <meta name="author" content="https://github.com/gitbrent">
  <meta name="website" content="https://github.com/gitbrent/PptxGenJS/">
  <meta name="version" content="3.11.0">
  - <meta name="updated" content="2022-06-05">
  + <meta name="updated" content="2022-06-07">
  <link rel="icon" href="images/favicon-32x32.png" sizes="32x32" type="image/png">
  <link rel="icon" href="images/favicon-16x16.png" sizes="16x16" type="image/png">
  <link rel="icon" href="images/favicon.png">
  </ul>
  </div>
  <div class="col">
  - <h6 class="text-primary">Multi-Type Chart</h6>
  + <h6 class="text-primary">Combo Chart</h6>
  <ul class="mb-0">
  <li>Slide 19 - Various Options</li>
  </ul>
  </div>
  <div class="col">
  - <h6 class="text-primary">Chart Options</h6>
  + <h6 class="text-primary">Misc Options</h6>
  <ul class="mb-0">
  <li>Slide 20 - Shadows and Transparent Color</li>
  </ul>
  