added app shortcuts

src/manifest.webmanifest

@@ -43,5 +43,15 @@
       "type": "image/png",
       "purpose": "maskable any"
     }
+  ],
+  "shortcuts": [
+    {
+      "name": "Apply New Leave",
+      "url": "/#/leave;type=new",
+      "icons": [{
+        "src": "https://cdn.swopt.com/media/icons/leave.png",
+        "sizes": "192x192"
+      }]
+    }
   ]
 }