docs: fix favicon (#2758)

Author: Uzlopak

index.html

@@ -7,8 +7,7 @@
   <meta name="description" content="A HTTP/1.1 client, written from scratch for Node.js.">
   <meta name="viewport" content="width=device-width, initial-scale=1.0, minimum-scale=1.0">
   <link rel="stylesheet" href="//cdn.jsdelivr.net/npm/docsify@4/lib/themes/vue.css">
-  <link rel="icon" type="image/png" href="https://nodejs.org/static/images/favicons/favicon-32x32.png"/>
-  <link rel="icon" type="image/png" href="https://nodejs.org/static/images/favicons/favicon-16x16.png" />
+  <link rel="icon" type="image/png" href="https://nodejs.org/static/images/favicons/favicon.png" />
   <style>
   </style>
 </head>