{   "short_name": "SKEGradReader",   "name": "SKEGradReader",   "description": "SKEGradReader",   "display": "standalone",   "start_url": "index.html",   "background_color": "black",   "theme_color": "black",   "icons": [     {       "src": "nsb/images/72.png",       "sizes": "72x72"     },     {       "src": "nsb/images/192.png",       "sizes": "192x192"     },     {       "src": "nsb/images/512.png",       "sizes": "512x512"     }   ] }