LibWeb: Add icon as possible resource type on the link tag

Author: https://github.com/avdg 🔰
Commit: 13847aa7e8
Pull-request: https://github.com/SerenityOS/serenity/pull/13462
Reviewed-by: https://github.com/TobyAsE
Reviewed-by: https://github.com/davidot ✅

Userland/Libraries/LibWeb/HTML/HTMLLinkElement.h

@@ -42,6 +42,7 @@ private:
             Preload = 1 << 2,
             DNSPrefetch = 1 << 3,
             Preconnect = 1 << 4,
+            Icon = 1 << 5,
         };
     };