Fix typo in Hiero Consensus Specifications title

[kantorcodes]

Summary

Changes

Checklist

• This change follows the process in docs/standards/hcs-4.md
• I used RFC 2119 language (MUST/SHOULD/MAY) for normative requirements
• The spec includes Status and Version
• The spec includes Backwards Compatibility / Migration guidance
• The spec includes Security Considerations (and Privacy Considerations if applicable)
• The spec includes Conformance requirements (what implementations MUST/SHOULD do)
• The spec includes a License section stating Apache-2.0
• If proposing publication, I included a Governance Record (PASS reference)
• I did not include secrets or private keys