docs/AGENTS.md is repo authoring guidance, but everything in docs/ gets published #2758

What changed

In 51a0394 (Update SDK snapshot for Copilot CLI 1.0.88-2), this file was renamed:

.github/instructions/docs-style.instructions.md  ->  docs/AGENTS.md

The content was effectively unchanged (+6/-5). It is still the same thing it was before: authoring guidance for people and agents writing docs in this repo.

Why the new location is a problem

Everything under docs/ is synced into GitHub's docs pipeline and published to docs.github.com — as the file itself states:

These docs are synced to github/docs-internal via a normalization pipeline, so they must follow the conventions below to be compatible with docs.github.com.

That sync copies the whole docs/ directory and excludes only .validation/ and developer-docs/. Its previous home, .github/instructions/, was never in scope. So the rename has two consequences:

1. It becomes a published page. docs/AGENTS.md is on track to render as a public SDK documentation page, where readers would get a contributor style guide ("Only code inside <details> blocks", "Blocks must be consecutive") presented as end-user SDK docs.

2. It stalled the sync. Because the file documents the <details> → tabbed-code-sample convention, its prose necessarily contains many inline `<details>` mentions. Our normalizer treated those as real tags and hung on the file; one sync run had to be cancelled after ~3 hours.

To be clear, (2) is our bug, and it is already fixed — the parser should never have hung on valid Markdown, and it no longer does. This issue is only about (1), which the fix does not address: the file is still slated for publication.

Suggested fix

Move it back out of docs/. Either:

• .github/instructions/docs-style.instructions.md — its previous home, or
• repo-root AGENTS.md — where the AGENTS.md convention expects it, and which is outside the synced directory.

Either keeps it discoverable to agents and contributors without publishing it as user-facing documentation.