Add manifest.json, icons and install button, flatten client/src

client/public/manifest.json

@@ -0,0 +1,21 @@
+{
+  "short_name": "Dispatch",
+  "name": "Dispatch",
+  "icons": [
+    {
+      "src": "icon_192.png",
+      "type": "image/png",
+      "sizes": "192x192"
+    },
+    {
+      "src": "icon_512.png",
+      "type": "image/png",
+      "sizes": "512x512"
+    }
+  ],
+  "start_url": "/",
+  "background_color": "#f0f0f0",
+  "display": "standalone",
+  "scope": "/",
+  "theme_color": "#f0f0f0"
+}