Add shortcut icon

Author: emp0ry

docs/index.html

@@ -57,6 +57,7 @@
 
     <!-- Favicon -->
     <link rel="icon" type="image/x-icon" href="img/icon.ico">
+    <link rel="shortcut icon" type="image/x-icon" href="img/icon.ico">
 
     <!-- Google Fonts: Poppins -->
     <link href="https://fonts.googleapis.com/css2?family=Poppins:wght@400;600&display=swap" rel="stylesheet">