message: formatted, minor bootstrap update
diff: <link rel="shortcut icon" href="%PUBLIC_URL%/favicon.ico" />
  <meta name="viewport" content="width=device-width, initial-scale=1" />
  <meta name="theme-color" content="#000000" />
  - <meta
  - name="description"
  - content="Web site created using create-react-app"
  - />
  + <meta name="description" content="PptxGenJS React Demo (create a react app)" />
  <link rel="apple-touch-icon" href="logo192.png" />
  <!--
  manifest.json provides metadata used when your web app is installed on a
  work correctly both with client-side routing and a non-root public URL.
  Learn how to configure a non-root public URL by running `npm run build`.
  -->
  - <title>React App</title>
  - <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootswatch/4.3.1/darkly/bootstrap.min.css"/>
  + <title>pptxgenjs react demo app</title>
  + <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootswatch/4.5.2/darkly/bootstrap.min.css" />
  <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/prism/1.15.0/themes/prism-okaidia.min.css">
  <script src="https://cdnjs.cloudflare.com/ajax/libs/prism/1.15.0/prism.min.js"></script>
  </head>
  