Update favicon description (facebook#3374)

Author: piotr-cz

template/public/manifest.json

@@ -4,8 +4,8 @@
   "icons": [
     {
       "src": "favicon.ico",
-      "sizes": "64x64",
-      "type": "image/png"
+      "sizes": "64x64 32x32 24x24 16x16",
+      "type": "image/x-icon"
     }
   ],
   "start_url": "./index.html",