create pwa manifests code example

Example: manifest for pwa

{  "short_name": "WAM",  "name": "Web App Manifest",  "theme_color": "#eb5252",  "background_color": "#000000",  "display": "fullscreen",  "Scope": "/",  "orientation": "portrait",  "icons": [    {      "src": "images/android/android-launchericon-48-48.png",      "type": "image/png",      "sizes": "48x48"    },    {      "src": "images/android/android-launchericon-96-96.png",      "type": "image/png",      "sizes": "96x96"    },    {      "src": "images/android/android-launchericon-192-192.png",      "type": "image/png",      "sizes": "192x192"    }  ],  "start_url": "index.html?utm_source=homescreen"}