docs: add docs for check-store

.github/workflows/check-store-README.md

@@ -0,0 +1,58 @@
+# MageCheck Store
+
+A Github Workflow that runs various kinds of quality checks for a Magento Store.
+
+Unlike [MageCheck Extension](./check-extension-README.md), this workflow automatically detects the Magento version from your store's `composer.lock` — no matrix computation required in the calling workflow.
+
+## Inputs
+
+See the [check-store.yaml](./check-store.yaml)
+
+| Input               | Description                                                                            | Required | Default   |
+| ------------------- | -------------------------------------------------------------------------------------- | -------- | --------- |
+| path                | The folder of the Magento store that you are testing                                   | false    | .         |
+| composer_cache_key  | A key to version the composer cache. Can be incremented if you need to bust the cache. | false    | \_mageos  |
+| store_artifact_name | If provided, download store files from this artifact instead of using actions/checkout | false    | ""        |
+
+## Secrets
+
+| Input         | Description                                                                                                                             | Required | Default |
+| ------------- | --------------------------------------------------------------------------------------------------------------------------------------- | -------- | ------- |
+| composer_auth | Your composer credentials (typically a stringified json object of the contents of your auth.json)                                       | false    | NULL    |
+
+## Checks Run
+
+- **Unit Tests** — runs PHPUnit against custom code in `app/code`. Skipped automatically if no test files are found.
+- **Coding Standard** — runs the Magento Coding Standard against `app/code`. Uses your `phpcs.xml` (or `.phpcs.xml`, `phpcs.xml.dist`, `.phpcs.xml.dist`) if one exists, otherwise a sensible default is generated.
+
+## Usage
+
+```yml
+name: Check Store
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+jobs:
+  check-store:
+    uses: graycoreio/github-actions-magento2/.github/workflows/check-store.yaml@main
+    secrets:
+      composer_auth: ${{ secrets.COMPOSER_AUTH }}
+```
+
+### Usage with a store artifact
+
+If your pipeline builds or prepares the store in a prior job and uploads it as an artifact, you can pass the artifact name instead of relying on `actions/checkout`:
+
+```yml
+jobs:
+  check-store:
+    uses: graycoreio/github-actions-magento2/.github/workflows/check-store.yaml@main
+    secrets:
+      composer_auth: ${{ secrets.COMPOSER_AUTH }}
+```

README.md

@@ -5,6 +5,7 @@
 ![GitHub release (latest SemVer)](https://img.shields.io/github/v/release/graycoreio/github-actions-magento2)
 [![Integration Test](https://img.shields.io/github/actions/workflow/status/graycoreio/github-actions-magento2/_internal-integration.yaml?label=Integration%20Test&labelColor=1a1a1a)](https://github.com/graycoreio/github-actions-magento2/actions/workflows/_internal-integration.yaml)
 [![MageCheck](https://img.shields.io/github/actions/workflow/status/graycoreio/github-actions-magento2/_internal_check_extension.yaml?label=Check%20Extension%20Test&labelColor=1a1a1a)](https://github.com/graycoreio/github-actions-magento2/actions/workflows/_internal_check_extension.yaml)
+[![MageCheck Store](https://img.shields.io/github/actions/workflow/status/graycoreio/github-actions-magento2/_internal-check-store.yaml?label=Check%20Store%20Test&labelColor=1a1a1a)](https://github.com/graycoreio/github-actions-magento2/actions/workflows/_internal-check-store.yaml)
 
 </div>
 
@@ -20,6 +21,7 @@ Opinionated Github Actions and Workflows to make building, testing, and maintain
 | -------------------------------------------------------------------- | ------------------------------------------------------------------------------------ |
 | [Integration Test](./.github/workflows/integration-README.md)        | A Github Workflow that runs the Integration Tests of a Magento Package               |
 | [MageCheck Extension](./.github/workflows/check-extension-README.md) | A Github Workflow that runs various kinds of quality checks for a Magento Extension. |
+| [MageCheck Store](./.github/workflows/check-store-README.md)         | A Github Workflow that runs various kinds of quality checks for a Magento Store.     |
 
 ## Actions