docs: Split Keeper page into sub-sections

[Harsh-pa-thak]

Fixes #5904

The Keeper page was a single ~1,400 line page mixing many unrelated concerns. This splits it into four focused sub-pages — Overview, Setup, Reference, and Guides — following the same pattern as the ClickHouse Operator section.

No content was changed, only re-organised.

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Note

Low Risk
Documentation-only restructure with permanent redirects; no runtime or product behavior changes.

Overview
Reorganizes the ~1,400-line ClickHouse Keeper doc into four pages under docs/guides/sre/keeper/: Overview (/guides/sre/keeper/overview), Setup, Reference, and Guides, with the former index.md content removed in favor of this structure (same pattern as the Kubernetes Operator section).

Navigation and links now point at the overview entry: FAQ operations, manage-and-deploy index, and the TLS guide’s 4lw link target Reference for four-letter-word commands. The sidebar replaces a single keeper/index item with a collapsible ClickHouse Keeper category that autogenerates from the guides/sre/keeper directory; _category_.yml drops the old generated-index slug.

Redirects in vercel.json send legacy URLs (clickhouse-keeper, /docs/guides/sre/clickhouse-keeper, /docs/en/operations/clickhouse-keeper/, etc.) to /docs/guides/sre/keeper/overview.

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[CLAassistant]

All committers have signed the CLA.

[dhtclk]

Thanks for the contribution for the most part looks good! Just a few things:

• Please add a redirect from /guides/sre/keeper/clickhouse-keeper to the new overview page, else existing links pointed to that old slug will break.
• There is an accidental deletion that should not be included with this change.

[dhtclk]

This was deleted when it shouldn't have been. Likely a stale fork.

[Harsh-pa-thak]

Thanks for catching both of these! I'll add the redirect for the old Keeper slug and restore the changelog file — that deletion was unintentional, likely from my fork being out of sync. Pushing a fix shortly

[vercel]

@Harsh-pa-thak is attempting to deploy a commit to the ClickHouse Team on Vercel.

A member of the Team first needs to authorize it.

[dhtclk]

Just one small thing that's breaking CI!

[dhtclk]

Suggested change

	doc_type: 'overview'
	doc_type: 'landing-page'

the doc_type: 'overview' is failing CI (DocsCheck). overview isn't a valid value; it needs to be one of guide, reference, changelog, or landing-page. Since this is the section's landing page, landing-page is the right fit.

[Harsh-pa-thak]

Thanks for flagging the doc_type issue!

While addressing that, I noticed the DocsCheck build was also failing due to 3 additional frontmatter violations in the same directory. I've fixed all of them in this commit:

02_setup.md — sentence casing: "ClickHouse Keeper Setup" → "ClickHouse Keeper setup"
03_reference.md — sentence casing: "ClickHouse Keeper Reference" → "ClickHouse Keeper reference"
04_guides.md — sentence casing: "ClickHouse Keeper Guides" → "ClickHouse Keeper guides"
All changes are strictly limited to frontmatter fields and are in line with the style guide. No content was modified.