add pwa manifest

Author: johnpc

output/bookgrab-logo.png

@@ -0,0 +1,30 @@
+{
+  "name": "BookGrab",
+  "short_name": "BookGrab",
+  "description": "Simple book search and download app for MyAnonyMouse",
+  "start_url": "/",
+  "display": "standalone",
+  "background_color": "#ffffff",
+  "theme_color": "#000000",
+  "orientation": "portrait-primary",
+  "categories": ["books", "entertainment", "utilities"],
+  "icons": [
+    {
+      "src": "/icons/icon-192x192.png",
+      "sizes": "192x192",
+      "type": "image/png",
+      "purpose": "maskable any"
+    },
+    {
+      "src": "/icons/icon-512x512.png",
+      "sizes": "512x512",
+      "type": "image/png",
+      "purpose": "maskable any"
+    },
+    {
+      "src": "/icons/apple-touch-icon.png",
+      "sizes": "180x180",
+      "type": "image/png"
+    }
+  ]
+}

public/favicon-16x16.png

@@ -0,0 +1,25 @@
+const CACHE_NAME = 'bookgrab-v1';
+const urlsToCache = [
+  '/',
+  '/manifest.json',
+  '/icons/icon-192x192.png',
+  '/icons/icon-512x512.png',
+];
+
+self.addEventListener('install', (event) => {
+  event.waitUntil(
+    caches.open(CACHE_NAME)
+      .then((cache) => cache.addAll(urlsToCache))
+  );
+});
+
+self.addEventListener('fetch', (event) => {
+  event.respondWith(
+    caches.match(event.request)
+      .then((response) => {
+        // Return cached version or fetch from network
+        return response || fetch(event.request);
+      }
+    )
+  );
+});