Do not use AI tools to generate documentation

[tdcmeehan]

Description

Update contributing guide to call out AI tools. These generate low quality documentation and they are easily identifiable.

Motivation and Context

There have been a few examples of PRs which attempt to add documentation through the assistance of an AI tool. We should have more clear guidance that such documentation will not be merged by this project.

Impact

Avoid low quality documentation, alert developers that such PRs will not be merged.

Test Plan

N/A

Contributor checklist

• Please make sure your submission complies with our contributing guide, in particular code style and commit standards.
• PR description addresses the issue accurately and concisely. If the change is non-trivial, a GitHub Issue is referenced.
• Documented new properties (with its default value), SQL syntax, functions, or other functionality.
• If release notes are required, they follow the release notes guidelines.
• Adequate tests were added if applicable.
• CI passed.

Release Notes

== NO RELEASE NOTE ==