v2.8.21-canary.19

<!-- Release notes generated using configuration in .github/release.yml at v2.8.21-canary.19 -->

What's Changed

Changelog

• docs: Add AI agent detection and automatic markdown rewrites by @molebox in https://github.com/vercel/turborepo/pull/12462
• fix: Resolve generator name conflicts across workspaces by @anthonyshew in https://github.com/vercel/turborepo/pull/12467

Full Changelog: https://github.com/vercel/turborepo/compare/v2.8.21-canary.18...v2.8.21-canary.19