Remove polyfill.io recommendation from the docs

[jttommy]

This is great work, btw. Been a huge fan of BSN since like 2018 or something. In your kute docs you link to polyfill.io here:

https://thednp.github.io/kute.js/index.html

In 2024 there was a massive vulnerability on polyfill.io. We had to stop using it at work.
https://fossa.com/blog/polyfill-supply-chain-attack-details-fixes/

I would recommend removing that from your docs. Maybe a simple list of recommended polyfills would help.