Docs: track aictrl.dev referrals from the CLI repository

[byapparov]

Context

Outbound links from this repository to aictrl.dev do not identify GitHub CLI repository referrals in analytics.

Goal

Add consistent UTM parameters to the repository's documentation link while keeping the legal notice stable.

Acceptance criteria

• Links use utm_medium=referral, utm_source=github, and utm_campaign=cli.
• The README link uses utm_content=readme.
• The license copyright notice remains unchanged and untagged.

Out of scope

Runtime analytics, application behavior changes, or marketing parameters in legal notices.