Update jsDelivr links

[LukasDrgon]

jsDelivr switched to a fully automated system, that can serve files from npm and GitHub. This means all future releases will be available automatically, but will use a new link structure.
I noticed you have some links at https://www.berriart.com/sidr/, and just wanted to let you know, that for future versions the correct links are:

• https://cdn.jsdelivr.net/npm/sidr@2.2.1/dist/jquery.sidr.min.js
• https://cdn.jsdelivr.net/npm/sidr@2.2.1/dist/stylesheets/jquery.sidr.dark.min.css

You can find links for all files at https://www.jsdelivr.com/package/npm/sidr.

Feel free to ping me if you have any questions regarding this change.