Fix start URL in manifest.json (#282)

www/public/manifest.json

@@ -29,7 +29,7 @@
   ],
   "theme_color": "#ffffff",
   "background_color": "#ffffff",
-  "start_url": "/shhh",
+  "start_url": "/",
   "display": "standalone",
   "orientation": "portrait"
-}
+}