Make this repo the source of truth for docs content standards

[samironsoctopus]

What this does

Moves the Octopus documentation content standards into this repository and makes it their single source of truth. They currently live in both the octopus-docs-standards Claude plugin skill and Confluence, and the copies drift.

Task 1 — the standards

Adds ten standards to contributing/standards/, migrated verbatim from the skill.

One difference between the installed skill copies needed reconciling: a stale local copy carried an extra "3 years old or newer" guideline in version-notes.md that the committed plugin version and the shipped marketplace build had already dropped. This takes the current version, so that line is not present here.

Also adds contributing/standards/README.md, which carries the routing and orientation that previously existed only inside the skill's SKILL.md — the content model, how to pick a page type, the guide-versus-tutorial boundary, and a table of which standards apply to which task. Without it, a contributor not using Claude Code got an alphabetical file list and no way in. It routes and orients only, and never restates substance from the ten standards.

Task 2 — top-level README

Adds a short Documentation standards section, and repoints the existing Docs page layout guidelines section at the folder. That section previously sent people to the skill plus a Confluence search, which is now the wrong direction.

Task 3 — CONTRIBUTING

• External contributor instructions now come before Octopus staff instructions.
• Adds a line pointing contributors at the standards before they submit.
• Replaces both INSERT-LINK-HERE placeholders with a Confluence search reference, so no broken links ship.

Lint and spellcheck exclusions

contributing/standards/** is excluded from markdownlint and cspell, following the src/pages/docs/api/** precedent already present in both configs.

CI checks every changed .md file repo-wide, and the migrated files intentionally contain fences without a language, a compact-style example table, and a repeated "Version notes" heading demonstrating two format variants. Linting them would mean editing illustrative content rather than fixing defects, and would break the verbatim migration.

A directory glob was chosen over enumerating the ten filenames deliberately: an enumerated list would need updating in two configs every time a new page-type standard ships, or CI fails on verbatim content.

README.md in that folder is our own prose rather than migrated content, so it was checked against both markdownlint and cspell out-of-tree and passes cleanly. It is not covered by CI going forward, which is the tradeoff of the directory glob.

Sequencing

This needs to merge before the octopus-docs-standards skill is repointed at these files, otherwise the skill's references break.

Reviewer notes

• The ten standards are byte-for-byte identical to the plugin source, verified with diff. The only judgment call in them is the version-notes.md reconciliation described above.
• The CONTRIBUTING reorder was verified line-by-line to confirm it changed only the four intended lines and dropped nothing.
• All relative links resolve.
• Pre-existing and left alone: CONTRIBUTING refers to "Required checks" and "Deploying to preview environment" as being "below", but both sections live in the top-level README. Happy to fix in this PR or separately.

[team-marketing-branch-protections]

Pull request environment is available at https://stoctodocspr3434.z22.web.core.windows.net.

You can view the ephemeral environment status in Octopus Deploy.

This environment will be automatically deprovisioned when the pull request is closed, or after 7 days of inactivity.