Merge #11094: Docs: Hash in ZMQ hash is raw bytes, not hex

Summary:
PR11094 backport https://github.com/bitcoin/bitcoin/pull/11094/files
06a3aec Docs: Hash in ZMQ hash is raw bytes, not hex (Karel Bílek)

Pull request description:

Transaction hex cannot be in hexadecimal, that would be 64 bytes. In reality it's just raw bytes.

Test Plan: read

Reviewers: deadalnix, jasonbcox, Fabien, #bitcoin_abc

Reviewed By: deadalnix, #bitcoin_abc

Differential Revision: https://reviews.bitcoinabc.org/D3482