Issue Summary

Polyfill.io was bought by a Chinese company earlier this year and has since then gone on to inject malicious code into the polyfill code it delivers. Polyfill.io should be removed where possible, if not Fastly and Cloudflare have set up mirrors of safe code, see:

• Polyfill supply chain attack hits 100K+ sites
• Polyfill.io JavaScript supply chain attack impacts over 100K sites

The section on Browser Compatibility instructs users to use polyfill.io, which should be changed either to one of the trustworthy mirrors or the section should be dropped if it is unlikely that people will still need this.

Steps to Reproduce:

This concerns the documentation, specifically the section on Browser Compatibility.

Technical details:

none, this is about the documentation

Supporting information:

see links posted above, also this issue over at Material for MkDocs