title: What is public/manifest.json file in create-react-app?
body: <p>I know that chrome extensions use 'manifest.json`, but here, it is used as something else as well. </p>
  
  <p>contents -</p>
  
  <pre><code>{
    "short_name": "React App",
    "name": "Create React App Sample",
    "icons": [
      {
        "src": "favicon.ico",
        "sizes": "192x192",
        "type": "image/png"
      }
    ],
    "start_url": "./index.html",
    "display": "standalone",
    "theme_color": "#000000",
    "background_color": "#ffffff"
  }
  </code></pre>
  
  <p>When I change some value, page update, but nothing changes.</p>