Document hidden frontmatter property

[ethanpalm]

Documentation changes

This PR documents how to hide pages with hidden: true

---

For Reviewers

When reviewing documentation PRs, please consider:

✅ Technical accuracy

• Code examples work as written
• Commands and configurations are correct
• Links resolve to the right destinations
• Prerequisites and requirements are accurate

✅ Clarity and completeness

• Instructions are clear and easy to follow
• Steps are in logical order
• Nothing important is missing
• Examples help illustrate the concepts

✅ User experience

• A new user could follow these docs successfully
• Common gotchas or edge cases are addressed
• Error messages or troubleshooting guidance is helpful

---

Note

Low Risk
Documentation-only changes (wording, examples, and cross-links) with no runtime behavior impact; main risk is minor confusion if anchors/links are incorrect.

Overview
Documents how to hide pages using hidden: true frontmatter (in addition to omitting pages from docs.json navigation), including a YAML example and clarifying that hidden pages are not search-indexed by default.

Updates SEO docs to clarify noindex usage and explicitly note that hidden: true implies noindex, and adds hidden/noindex to the frontmatter reference in organize/pages.mdx alongside general copy edits for clarity.

^{Written by Cursor Bugbot for commit 3469036. This will update automatically on new commits. Configure here.}