docs: update GOVERNANCE.md with AI attribution reference

Add pointer to CONTRIBUTING.md attribution conventions in the
existing 'Use of AI tools' paragraph.

Assisted-by: Claude Code
Signed-off-by: Alex Bozarth <ajbozart@us.ibm.com>

Author: ajbozarth

GOVERNANCE.md

@@ -75,7 +75,7 @@ When a PR is accepted, the maintainers inherit both an asset and a liability: th
 
 Contributors are responsible for every line they submit. Do not ask others to read and maintain code or documentation that you have not taken the time to read, understand, and refine yourself. This applies regardless of how the code was produced — whether written by hand or generated with AI tools.
 
-**Use of AI tools:** We neither prohibit nor discourage the use of AI coding assistants. However, AI-generated code is not exempt from this standard. If you use AI tools to produce code or documentation, you are expected to review, understand, and take full ownership of the output before submitting it for review. The reviewer's time is not the place to discover what the AI wrote on your behalf.
+**Use of AI tools:** We neither prohibit nor discourage the use of AI coding assistants. However, AI-generated code is not exempt from this standard. If you use AI tools to produce code or documentation, you are expected to review, understand, and take full ownership of the output before submitting it for review. The reviewer's time is not the place to discover what the AI wrote on your behalf. For attribution conventions, see [CONTRIBUTING.md](CONTRIBUTING.md).
 
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