title: How to add custom css file in Ext JS 5 via app.json?
body: <p>In app.json, Ext JS 5 provide a way to include CSS file using object. Here my code in app.json</p>
  
  <pre><code>"css": [
          {
              "path": "bootstrap.css",
              "bootstrap": true
          },
          {
              "path": "app.css"
          }
      ],
  </code></pre>
  
  <p>It seems app.css does not include in HTML.</p>
  
  <p>any idea?</p>