chore(docs) Direct contributors to the docs authoring skills (#50600)

Prerequisite for
[DOCS-1289](https://linear.app/supabase/issue/DOCS-1289/get-the-linter-to-fix-what-it-flags-or-retirereplace-the-linter).

## Problem

The `write-the-docs` and `edit-the-docs` skills carry the docs style
guide, so a contributor who uses them writes to the guide without having
read it. Right now nothing points a contributor at them.
`apps/docs/CONTRIBUTING.md` describes the skills as an option for agent
users, halfway down a 559-line page, and no other contributor-facing
file mentions them at all.

## Solution

- **CodeRabbit reminder.** One path instruction for
`apps/docs/content/**/*.mdx`. When a page collects two or more style,
terminology, or structure issues, CodeRabbit adds a single comment
pointing the author at `/write-the-docs` or `/edit-the-docs`. A single
nit gets no pointer, so the comment reads as a signal rather than
boilerplate.
- **Docs CONTRIBUTING.** The intro lists the skills by task, draft
through self-review, before the style rules, and links the existing
skills section for framing and architecture. The section opener now
reads as an expectation rather than a conditional, with the agent
mechanics moved to a second paragraph.
- **Root CONTRIBUTING.** A pre-flight check under Pull Requests, with
the same task list nested under it. Matches the docs checklist item in
#50591.
- **Word list.** Names the skills that apply the list.
- **Docs README and DEVELOPERS.** One sentence in each Contributing
section.

**Not in this PR:** CodeRabbit reminds, it doesn't enforce. Feeding the
two `SKILL.md` files to `knowledge_base.code_guidelines` would make it
review docs content against the style guide. That's a decision for
DOCS-1289 itself.

**Verification caveat:** this PR changes no MDX under
`apps/docs/content/`, so the new path instruction doesn't fire on its
own review.

## Manual testing

1. See all new content references in the diff.
2. Review for clarity and value.
3. Consider suggesting other ways to promote the usage of this skill to
all docs contributors.

.coderabbit.yaml

@@ -69,6 +69,14 @@ reviews:
           for both runtimes until the final cleanup pass (tracked in FE-3106).
         Keep this a reminder to verify, not a hard blocker: if no mirror is required,
         say so briefly rather than forcing a change.
+    - path: 'apps/docs/content/**/*.mdx'
+      instructions: |
+        Flag style, terminology, and structure issues as usual. When a page has two or
+        more of them, add one comment pointing the author at the `/write-the-docs` skill
+        for new content or `/edit-the-docs` for an existing page (canonical files in
+        `.agents/skills/`); both apply apps/docs/CONTRIBUTING.md and
+        apps/docs/WORD_LIST.md. Skip that pointer on a single issue, so it stays a
+        signal that the author isn't using the skills rather than boilerplate.
     - path: '{apps,packages}/**/*.{tsx,jsx,css,mdx}'
       instructions: |
         When reviewing UI changes, flag these accessibility gaps. Comments are

CONTRIBUTING.md

@@ -27,5 +27,9 @@ Prior to submitting your PR, please conduct the following pre-flight checks:
 
 - Run `npm run build` locally to ensure that your code builds successfully without having to wait on us to approve Vercel Preview deploys.
 - Ensure that the Prettier tests run successfully on your PR.
+- If your PR changes docs content, use the docs authoring [agent skills](https://github.com/supabase/supabase/tree/master/.agents/skills). They apply the [docs style guide](https://github.com/supabase/supabase/blob/master/apps/docs/CONTRIBUTING.md) for you.
+  - `/write-the-docs` to draft a new page, or `/edit-the-docs` to revise an existing page.
+  - `/test-the-docs` to run any snippets you added.
+  - `/review-the-docs` to self-review before you open the PR.
 
 Running these before you create the PR will help reduce back and forth with the team.

apps/docs/CONTRIBUTING.md

@@ -4,7 +4,14 @@ Our docs help developers to get started and keep succeeding with Supabase. We we
 
 If you'd like to contribute, see our list of [recommended issues](https://github.com/supabase/supabase/issues?q=is%3Aopen+is%3Aissue+label%3Adocumentation+label%3A%22help+wanted%22). We also welcome you to open a PR or a new issue with your question.
 
-Here are some general guidelines on writing docs for Supabase.
+Here are some general guidelines on writing docs for Supabase. If you write with an AI coding agent, these skills apply the guidelines for you:
+
+- `/write-the-docs` to draft a new page.
+- `/edit-the-docs` to revise an existing page.
+- `/test-the-docs` to run the snippets you wrote.
+- `/review-the-docs` to check your work before you open a pull request.
+
+See [AI agent skills for docs authoring](#ai-agent-skills-for-docs-authoring) for the full set, including the skills that help you frame a page and place it in the information architecture.
 
 ## General principles
 
@@ -83,7 +90,9 @@ The `using` clause accepts any expression that returns a boolean.
 
 ## AI agent skills for docs authoring
 
-If you're using an AI coding agent that reads `.agents/skills/`, such as Claude Code, Cursor, or Codex, invoke skills with `/name`, for example `/write-the-docs`. The canonical files live in `.agents/skills/` (`.claude/skills` is a symlink).
+Use these skills for every docs change you make with an AI coding agent: `/write-the-docs` to draft, and `/edit-the-docs` to revise an existing page. They apply this guide and the [word list](./WORD_LIST.md), so you don't have to hold either one in your head.
+
+Skills work in any agent that reads `.agents/skills/`, such as Claude Code, Cursor, or Codex. Invoke a skill with `/name`, for example `/write-the-docs`. The canonical files live in `.agents/skills/` (`.claude/skills` is a symlink).
 
 ### Write the docs skills
 

apps/docs/DEVELOPERS.md

@@ -57,4 +57,4 @@ for coverage and skipped rules.
 
 ## Contributing
 
-For repo organization and style guide, see the [contributing guide](https://github.com/supabase/supabase/blob/master/apps/docs/CONTRIBUTING.md).
+For repo organization and style guide, see the [contributing guide](https://github.com/supabase/supabase/blob/master/apps/docs/CONTRIBUTING.md). If you write with an AI coding agent, use the `/write-the-docs` skill to draft, `/edit-the-docs` to revise an existing page, and `/review-the-docs` to self-review before you open a PR.

apps/docs/README.md

@@ -20,4 +20,4 @@ It also means that we can switch to any documentation system we want. On this si
 
 ## Contributing
 
-To contribute to docs, see the [developers' guide](https://github.com/supabase/supabase/blob/master/apps/docs/DEVELOPERS.md) and [contributing guide](https://github.com/supabase/supabase/blob/master/apps/docs/CONTRIBUTING.md).
+To contribute to docs, see the [developers' guide](https://github.com/supabase/supabase/blob/master/apps/docs/DEVELOPERS.md) and [contributing guide](https://github.com/supabase/supabase/blob/master/apps/docs/CONTRIBUTING.md). If you write with an AI coding agent, use the `/write-the-docs` skill to draft and `/edit-the-docs` to revise an existing page.

apps/docs/WORD_LIST.md

@@ -9,6 +9,8 @@ conflict, follow `CONTRIBUTING.md`. Match literal code, API names, UI labels, an
 third-party product names even when they differ from this guidance, and format them
 as code or UI text as appropriate.
 
+The `/write-the-docs` and `/edit-the-docs` agent skills apply this list as you draft.
+
 Many unambiguous rules in this list are checked by `supa-mdx-lint`. Run
 `pnpm lint:mdx` from `apps/docs` after editing MDX. A lint warning still requires
 judgment: rewrite the sentence instead of applying a replacement that changes its