map context menu with coordinates, closes #149

website/src/lib/components/CoordinatesPopup.svelte

@@ -0,0 +1,18 @@
+<script lang="ts">
+	import { map } from '$lib/stores';
+	import { trackpointPopup } from '$lib/components/gpx-layer/GPXLayerPopup';
+	import { TrackPoint } from 'gpx';
+
+	$: if ($map) {
+		$map.on('contextmenu', (e) => {
+			trackpointPopup?.setItem({
+				item: new TrackPoint({
+					attributes: {
+						lat: e.lngLat.lat,
+						lon: e.lngLat.lng
+					}
+				})
+			});
+		});
+	}
+</script>