[readme/mirrors]: some listed mirrors are not working

[burtek]

Official Instance

• [ ] The bug is reproducible on the official hosted instance, or is API-related.

Describe the bug

Some mirrors listed in the README.md mirrors section don't work

1. vercel and netlify mirrors return unbypassable SSL errors (expired certs / wrong domain)
2. render mirror returns Cloudflare prohibited IP error

To Reproduce

Visit https://vc.piped.video/, https://re.piped.video/ or https://nf.piped.video/

Expected behavior

Piped website should appear

Logs/Errors

No response

Browser, and OS with Version.

Firefox 118, LMDE 6

Additional context

Not a bug but couldn't find a better/docs-related issue template