Add documentation about how to verify the release

[raulcd]

Describe the enhancement requested

I wasn't able to find notes on how to verify the release and followed the example and some steps provided on the Apache Doris wiki: https://github.com/apache/doris/wiki/How-to-verify-Apache-Release

I might have missed where this is documented but if it's missing, it might be interesting to add some documentation. I am happy to add some info about it. In any case would be good to add that link to the voting thread email to encourage people to vote.

Component(s)

No response