docs: typo in homepage (#313)

Author: lzhang

website/src/pages/index.mdx

@@ -28,7 +28,7 @@ import Helmet from 'react-helmet'
         <h2># Why?</h2>
         <ul>
           <li>Easy integration</li>
-          <li>Flexbility</li>
+          <li>Flexibility</li>
           <li>Performances</li>
         </ul>
       </Col>