Throw in all the preconnects, prefetches and preloads

index.html

@@ -4,6 +4,20 @@
 <title>BusRouter SG</title>
 <link rel="stylesheet" href="https://api.tiles.mapbox.com/mapbox-gl-js/v0.50.0/mapbox-gl.css">
 <link rel="stylesheet" href="assets/app.css">
+<link rel="preconnect" href="https://api.mapbox.com" crossorigin>
+<link rel="preconnect" href="https://a.tiles.mapbox.com" crossorigin>
+<link rel="preconnect" href="https://b.tiles.mapbox.com" crossorigin>
+<link rel="preconnect" href="https://events.mapbox.com" crossorigin>
+<link rel="preconnect" href="https://arrivelah.appspot.com" crossorigin>
+<link rel="dns-prefetch" href="https://api.mapbox.com" crossorigin>
+<link rel="dns-prefetch" href="https://a.tiles.mapbox.com" crossorigin>
+<link rel="dns-prefetch" href="https://b.tiles.mapbox.com" crossorigin>
+<link rel="dns-prefetch" href="https://events.mapbox.com" crossorigin>
+<link rel="dns-prefetch" href="https://arrivelah.appspot.com" crossorigin>
+<link rel="preload" as="fetch" href="data/3/services.final.json">
+<link rel="preload" as="fetch" href="data/3/stops.final.json">
+<link rel="preload" as="script" href="assets/app.js">
+<link rel="preload" as="image" href="assets/images/stop-small.png">
 <meta name="description" content="Explore bus stops and routes on the map for all bus services in Singapore">
 <meta name="google" value="notranslate">
 <meta property="og:type" content="website">