feat(lint): add vale-config skill

Covers Vale install and .vale.ini setup — StylesPath, built-in/
third-party/custom styles, BasedOnStyles activation. Setup half of
Vale support; vale-run (running/interpreting) is a separate skill.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FxG5T8EJDgkABXxuneuFfn

plugins/lint/skills/vale-config/references/configuration-reference.md

@@ -0,0 +1,78 @@
+---
+topic: configuration-reference
+source_keys:
+  - context7-websites-vale-sh
+---
+
+## Core Settings
+
+| Key | Type | Purpose |
+|---|---|---|
+| `StylesPath` | string | Path to all Vale-related resources (styles, dictionaries, vocab). |
+| `Packages` | string[] | Packages to download and install via `vale sync`. |
+| `Vocab` | string[] | Vocabularies to load. |
+| `MinAlertLevel` | enum | Minimum severity to report: `suggestion`, `warning`, or `error`. |
+| `IgnoredScopes` | enum | Inline-level HTML tags to ignore. |
+| `SkippedScopes` | enum | Block-level HTML tags to ignore entirely. |
+
+## Format Associations
+
+Map an unrecognized extension onto a supported one so Vale lints it with the right parser — an extension-level substitution only, it does not add new file-type support:
+
+```ini
+[formats]
+mdx = md
+```
+
+## Vocabularies
+
+Reference a named vocabulary (a folder of accept/reject word lists under `StylesPath`) via `Vocab`, then apply styles per glob:
+
+```ini
+StylesPath = styles
+
+Vocab = Blog
+
+[*]
+BasedOnStyles = Vale, MyStyle
+```
+
+## Local Overrides
+
+A project can layer a local `.vale.ini` that overrides `StylesPath`, adds packages, and changes `BasedOnStyles` for a subset of files — local settings merge with or override the global ones:
+
+```ini
+StylesPath = localpath
+
+Packages = write-good
+
+[*.md]
+BasedOnStyles = write-good
+```
+
+## Rule Header Fields
+
+Individual rule YAML files (under a style's directory) support these header fields:
+
+| Field | Required | Default | Purpose |
+|---|---|---|---|
+| `extends` | yes | — | Check this rule extends (e.g. `existence`). |
+| `message` | yes | — | Message shown when triggered; supports `%s` formatting per check type. |
+| `level` | no | `suggestion` | Severity: `suggestion`, `warning`, or `error`. |
+| `scope` | no | `text` | Scope the rule applies to (e.g. `heading`). |
+| `link` | no | — | URL with more info about the rule. |
+| `limit` | no | — | Max number of triggers per file. |
+| `vocab` | no | `true` | Set `false` to disable active vocabularies for this rule. |
+
+## Checks
+
+The underlying functions a rule's `extends` field can reference: `existence`, `substitution`, `occurrence`, `repetition`, `consistency`, `conditional`, `capitalization`, `metric`, `spelling`, `sequence`, `script`.
+
+## Built-in Style
+
+Vale ships with a default `Vale` style containing four rules, usable without `vale sync`:
+
+- `Vale.Spelling` — spell-checks against Hunspell-compatible dictionaries in `<StylesPath>/config/dictionaries`.
+- `Vale.Terms` — enforces the project's accepted vocabulary terms.
+- `Vale.Avoid` — enforces the project's rejected vocabulary terms.
+- `Vale.Repetition` — flags repeated words (e.g. "the the").