Link to planetplanet.org doesn't work, domain to expire soon

The link to planetplanet.org doesn't work (the site is dead) and hasn't for a while. The domain is about to expire (January 2026), so I worry that link might lead to something shady soon.

I suggest we either remove the link or point it to something different. Hugo suggested pointing it to an archive recording. Another option is linking to the code in this repository. Any other ideas?