Recovery from dead public gateways was introduced in #640.

What about scenarios when local gateway goes offline?

Current UX: error page provided by the browser

Right now, opening http://docs.ipfs.io.ipns.localhost:8080 when node is offline ends up with a generic error:

I believe we could improve UX of errors like this.

Improvement: custom error page aware of IPFS options

We should introduce a custom error page tho, to improve UX AND to give user a final say if they choose to start local node and retry, load from original server (if DNSLink), or a public gateway instead.

Custom error page could be used in all recovery contexts (when local node is offline, but also when remote server is down, but has DNSLink).