Add cross-device icons, theme + bg color

Author: addyosmani

src/manifest.json

@@ -2,13 +2,29 @@
   "short_name": "App shell",
   "name": "App shell",
   "start_url": "./?utm_source=web_app_manifest",
-  "icons": [
-    {
-      "src": "/images/chrome-touch-icon-192x192.png",
-      "sizes": "192x192",
-      "type": "image/png"
-    }
-  ],
+  "icons": [{
+        "src": "images/icon-128x128.png",
+        "sizes": "128x128",
+        "type": "image/png"
+      }, {
+        "src": "images/apple-touch-icon.png",
+        "sizes": "152x152",
+        "type": "image/png"
+      }, {
+        "src": "images/ms-touch-icon-144x144-precomposed.png",
+        "sizes": "144x144",
+        "type": "image/png"
+      }, {
+        "src": "images/chrome-touch-icon-192x192.png",
+        "sizes": "192x192",
+        "type": "image/png"
+      },{
+        "src": "images/chrome-splashscreen-icon-384x384.png",
+        "sizes": "384x384",
+        "type": "image/png"
+      }],
   "display": "standalone",
-  "orientation": "portrait"
+  "orientation": "portrait",
+  "background_color": "#3E4EB8",
+  "theme_color": "#2E3AA1"
 }