title: togpx not defined when trying to convert from geojson
body: <p>I'm trying to convert a geojson file to a gpx file in javascript using the togpx method that I found here: <a href="https://github.com/tyrasd/togpx" rel="nofollow noreferrer">https://github.com/tyrasd/togpx</a></p>
  <p>The problem is that when I try to save the file I receive the error <code>Uncaught ReferenceError: togpx is not defined</code>, even if I put the library in my browser page and installed as a command line tool.</p>
  <p>This is my code:</p>
  <pre><code>document.getElementById('export').onclick = function(e) {
              var gpxFile;
          // Extract GeoJson from drawnItems
          var data = drawnItems.toGeoJSON();
  
          // Stringify the GeoJson
          var convertedData = 'text/json;charset=utf-8,' + encodeURIComponent(JSON.stringify(data));
  
          gpxFile = togpx(convertedData);  //here I have the error
          var convertedGpx = 'text/xml;charset=utf-8,' + encodeURIComponent(gpxFile);
  
          // Create export
          document.getElementById('export').setAttribute('href', 'data:' + convertedGpx);
          document.getElementById('export').setAttribute('download', 'route.gpx');
      }
  </code></pre>
  <p>And I added the library using <code>&lt;script src='togpx.js'&gt;&lt;/script&gt;</code></p>
  <p>Can you help me with that?</p>