title: Openlayers5 and ol-ext
body: <p>Could anybody give me an example please how to integrate the ol-ext-library in OL5?</p>
  
  <p>So far I have downloaded the .css &amp; .js-Files from here: <a href="https://github.com/Viglino/ol-ext/tree/master/dist" rel="nofollow noreferrer">https://github.com/Viglino/ol-ext/tree/master/dist</a></p>
  
  <p>...to my openlayers/dist-directory.</p>
  
  <p>I try to link it in my html-file with:</p>
  
  <pre><code>      &lt;!-- ol-ext --&gt;
    &lt;link rel="stylesheet" href="openlayers/dist/ol-ext.css" /&gt;
    &lt;script type="text/javascript" src="openlayers/dist/ol-ext.js"&gt;&lt;/script&gt;
  </code></pre>
  
  <p>...and then I try "npm run build"...but I get so many errors.
  Has anybody included the ol-ext succesfully and could give me a hint?</p>