docs: 📄Documentation for TTL for finalized response

[rdsubhas]

I have a case where:

• example.com CNAME to a primary server.
• When I'm doing maintenance on that server, I change this CNAME to a backup server.

The primary and backup servers have static A records and their TTL is long.

But the example.com needs to be switched frequent and fast.

When I use the finalize plugin, is the effective TTL the shortest TTL encountered in the chain? Or the last A record's TTL?

If it's the final A record TTL, then this will get unpredictably cached for long in coredns cache, node local dns cache, client dns cache, any intermediaries.

It would be nice to document this, and if possible, use the shortest TTL encountered in the chain.

Thanks!