Add docs (#2)

* Update README.md

* Create LICENSE

* Update README.md

README.md

@@ -1 +1,22 @@
-# checkout
+# checkout
+
+This action checks out your repository so that your workflow operates from the root of the repository
+
+# Usage
+
+See [action.yml](action.yml)
+
+Basic:
+```yaml
+actions:
+- uses: actions/checkout@master
+- uses: actions/setup-node@master
+  with:
+    version: 10.x 
+- run: npm install
+- run: npm test
+```
+
+# License
+
+The scripts and documentation in this project are released under the [MIT License](LICENSE)