title: Adding custom markers to the mapbox gl
body: <p>I would like to add a custom marker to my map. I am using a mapbox gl script. </p>
  
  <p>The only documentation that I found related to this topic is this one <a href="https://www.mapbox.com/mapbox-gl-js/example/geojson-markers/" rel="noreferrer">https://www.mapbox.com/mapbox-gl-js/example/geojson-markers/</a>. </p>
  
  <p>I tried to customize given example and I managed to add a marker and modify it a little changing the size, but since I don't understand all the parameters, I don't know how to add my own marker. Is there any documentation that is more detailed?</p>
  
  <p>Here is my code:</p>
  
  <pre><code> &lt;script&gt;
      mapboxgl.accessToken = 'pk.eyJ1IjoiYWl3YXRrbyIsImEiOiJjaXBncnI5ejgwMDE0dmJucTA5aDRrb2wzIn0.B2zm8WB9M_qiS1tNESWslg';
      var map = new mapboxgl.Map({
          container: 'map', // container id
          style: 'mapbox://styles/aiwatko/cipo0wkip002ddfm1tp395va4', //stylesheet location
          center: [7.449932,46.948856], // starting position
          zoom: 14.3, // starting zoom
          interactive: true
      });       
  
      map.on('load', function () {
      map.addSource("markers", {
          "type": "geojson",
          "data": {
              "type": "FeatureCollection",
              "features": [{
                  "type": "Feature",
                  "geometry": {
                      "type": "Point",
                      "coordinates": [7.4368330, 46.9516040]
                  },
                  "properties": {
                      "title": "Duotones",
                      "marker-symbol": "marker",
  
                  }
              }]
          }
      });
  
      map.addLayer({
          "id": "markers",
          "type": "symbol",
          "source": "markers",
          "layout": {
              "icon-image": "{marker-symbol}-15",
              "icon-size": 3
          }
      });
  });
  &lt;/script&gt;
  </code></pre>
  
  <p>Thanks in advance!</p>
  
  <p>Oktawia</p>