feat: initial action implementation

README.md

@@ -0,0 +1,20 @@
+# checkout
+
+This action checks-out your repository under $GITHUB_WORKSPACE, so your workflow can access it.
+
+Only a single commit is fetched by default, for the ref/sha that triggered the workflow. The auth token
+is persisted in the local git config. This enables your scripts to run authenticated git commands.
+
+This action is only written in shell (bash).
+
+## Usage
+
+```yaml
+uses: actions/checkout:1.0.0
+with:
+  repository: ${{ github.server_url }}/${{ github.repository }}.git
+  token: ${{ github.token }}
+  path: .
+  ref: ${{ github.ref || github.sha }}
+```
+