Change the default start_url to . (facebook#3346)

Author: foochu

packages/react-scripts/template/README.md

@@ -2002,15 +2002,7 @@ If you’re using [Apache Tomcat](http://tomcat.apache.org/), you need to follow
 
 Now requests to `/todos/42` will be handled correctly both in development and in production.
 
-When users install your app to the homescreen of their device the default
-configuration will make a shortcut to `/index.html`. This may not work for
-client-side routers which expect the app to be served from `/`. Edit the web app
-manifest at [`public/manifest.json`](public/manifest.json) and change
-`start_url` to match the required URL scheme, for example:
-
-```js
-  "start_url": ".",
-```
+When users install your app to the homescreen of their device the default configuration will make a shortcut to `/`. This may not work if you don't use a client-side router and expect the app to be served from `/index.html`. In this case, the web app manifest at [`public/manifest.json`](public/manifest.json) and change `start_url` to `./index.html`.
 
 ### Service Worker Considerations
 
@@ -2024,8 +2016,7 @@ and work without requiring a network connection.
 
 If you are using the `pushState` history API and would like to enable service
 worker support for navigations to URLs like `/todos/42`, you need to
-[`npm eject`](#npm-run-eject) and enable the
-[`navigateFallback`](https://github.com/GoogleChrome/sw-precache#navigatefallback-string)
+[`npm eject`](#npm-run-eject) and enable the [`navigateFallback`](https://github.com/GoogleChrome/sw-precache#navigatefallback-string)
 and [`navigateFallbackWhitelist`](https://github.com/GoogleChrome/sw-precache#navigatefallbackwhitelist-arrayregexp)
 options of the `SWPreachePlugin` [configuration](../config/webpack.config.prod.js).
 

packages/react-scripts/template/public/manifest.json

@@ -8,7 +8,7 @@
       "type": "image/x-icon"
     }
   ],
-  "start_url": "./index.html",
+  "start_url": ".",
   "display": "standalone",
   "theme_color": "#000000",
   "background_color": "#ffffff"