Add light/dark favicon switch
Add light/dark favicon switch if the browser is using dark mode.
You can test it via DevTools -> More tools -> Rendering -> Emulate CSS media feature prefers-colors-scheme (dark/light).
Please don't forget to restart the webserver (Lighttpd) after uploading HTML files on the router.
Closes: #220 (closed).
Edited by Aleksandr Gumroian