Added PWA related category, orientation, screenshots, maskable icon and IARC rating ID.

Thanks to xet7 !

public/site.webmanifest

@@ -26,10 +26,31 @@
             "src": "/StoreLogo.scale-100.png",
             "sizes": "50x50",
             "type": "image/png"
+        },
+        {
+            "src": "/maskable_icon.png",
+            "sizes": "474x474",
+            "type": "image/png",
+            "purpose": "maskable"
         }
     ],
+    "screenshots" : [
+      {
+        "src": "/screenshot1.webp",
+        "sizes": "1280x720",
+        "type": "image/webp"
+      },
+      {
+        "src": "/screenshot2.webp",
+        "sizes": "1280x720",
+        "type": "image/webp"
+      }
+    ],
     "theme_color": "#ffffff",
     "background_color": "#ffffff",
     "start_url": "/sign-in",
-    "display": "standalone"
+    "display": "standalone",
+    "orientation": "any",
+    "categories": ["productivity"],
+    "iarc_rating_id": "70d7c4a4-3e5a-4714-a7dc-fa006613ba96"
 }