added frontend and made it usable

frontend/templates/map.html.twig

@@ -0,0 +1,24 @@
+{% extends 'base.html.twig' %}
+
+{% block title %}Map — VINDN{% endblock %}
+
+{% block head_extra %}
+{% include '_leaflet_head.html.twig' %}
+{% endblock %}
+
+{% block body %}
+  {% include '_map_stage.html.twig' %}
+{% endblock %}
+
+{% block scripts %}
+{% include '_leaflet_scripts.html.twig' %}
+<script type="application/json" id="map-data">{{ mapEventsJson|raw }}</script>
+<script>
+  Vindn.initRadiusMapStage({
+    events: Vindn.readEmbeddedJson('map-data'),
+    center: [{{ centerLat }}, {{ centerLon }}],
+    rangeKm: {{ rangeKm }},
+    maxRangeKm: {{ maxRangeKm }}
+  });
+</script>
+{% endblock %}