Add basic PWA support

index.html

@@ -10,7 +10,7 @@
 	<meta property="og:description" content="A Pokémon fangame heavily inspired by the roguelite genre. Battle endlessly while gathering stacking items, exploring many different biomes, and reaching Pokémon stats you never thought possible." />
 	<meta property="og:image" content="https://pokerogue.net/logo.png" />
 	<meta charset="UTF-8" />
-	<meta name="viewport" content="width=device-width, initial-scale=1.0" />
+	<meta name="viewport" content="width=device-width, initial-scale=1.0, viewport-fit=cover" />
 	<style type="text/css">
 		@font-face {
 			font-family: 'emerald';
@@ -23,6 +23,21 @@
 		}
 	</style>
 	<link rel="stylesheet" type="text/css" href="index.css" />
+  <link rel="manifest" href="manifest.json" />
+  <script>
+    if ("serviceWorker" in navigator) {
+      window.addEventListener("load", function () {
+        navigator.serviceWorker.register("/service-worker.js").then(
+          function (registration) {
+            console.log("ServiceWorker registration successful");
+          },
+          function (err) {
+            console.log("ServiceWorker registration failed: ", err);
+          },
+        );
+      });
+    }
+  </script>
 </head>
 
 <body>