Implemented support for repository defined node version files such as '.nvmrc'

README.md

@@ -55,6 +55,21 @@ steps:
 - run: npm test
 ```
 
+Node version file:
+
+The `node-version-file` input allows you to use a file within your repository which contains the version of node your project uses for example `.nvmrc`. If both the `node-version` and the `node-version-file` inputs are provided the `node-version` input is used.
+> The node version file is read from the project root
+
+```yaml
+steps:
+- uses: actions/checkout@v2
+- uses: actions/setup-node@v2
+  with:
+    node-version-file: '.nvmrc'
+- run: npm install
+- run: npm test
+```
+
 Matrix Testing:
 ```yaml
 jobs: