Point "Coding with AI agents" links at the rendered docs site (#13952)
CONTRIBUTING.md is a symlink to docs/source/en/conceptual/contribution.md.
GitHub renders a symlink blob as a path stub, not the target's content, so
the `#coding-with-ai-agents` anchor in the PR template and README landed on
an empty-looking page. Point those two anchored links at the rendered docs
site instead (the same URL the PR-issue-reminder bot already uses).
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>