Fetch favicon from GitHub instead of doom2d.org hosting service provider

See also: Doom2D/doom2d.github.io@bf2a93a.

Author: cher-nov

index.html

@@ -7,7 +7,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1, shrink-to-fit=no">
     <meta name="description" content="">
     <meta name="author" content="">
-    <link rel="shortcut icon" type="image/x-icon" href="https://doom2d.org/favicon.ico">
+    <link rel="shortcut icon" type="image/x-icon" href="https://doom2d.github.io/favicon.ico">