Update README

README.md

@@ -1,3 +1,61 @@
 # git-auto-commit-action
 
-> TBD
+This GitHub Action automatically commits files which have been changed during a Workflow run and pushes the Commit back to GitHub.
+The Committer is "GitHub Actions <actions@github.com>" and the Author of the Commit can be configured with environment variables.
+
+If no changes are available, the Actions does nothing.
+
+This Action has been inspired and adapted from the [auto-commit](https://github.com/cds-snc/github-actions/tree/master/auto-commit
+)-Action of the Canadian Digital Service.
+
+## Usage
+
+You have to have an Action in your Workflow, which changes some of your project files. 
+The most common use case for this, is when you're running a Linter or Code-Style fixer on GitHub Actions.
+
+In this example I'm running `php-cs-fixer` in a PHP project.
+
+```
+workflow "php-cs-fixer" {
+  on = "push"
+  resolves = [
+    "auto-commit-php-cs-fixer"
+  ]
+}
+
+action "php-cs-fixer" {
+  uses = "docker://oskarstark/php-cs-fixer-ga"
+}
+
+action "auto-commit-php-cs-fixer" {
+  needs = ["php-cs-fixer"]
+  uses = "stefanzweifel/git-auto-commit-action@v1.0.0"
+  secrets = ["GITHUB_TOKEN"]
+  env = {
+    COMMIT_MESSAGE = "Apply php-cs-fixer changes"
+    COMMIT_AUTHOR_EMAIL  = "john.doe@example.com"
+    COMMIT_AUTHOR_NAME = "John Doe"
+  }
+}
+```
+
+## Secrets
+
+The `GITHUB_TOKEN` secret is required. Add the secret in the Workflow Editor on github.com.
+
+## Environment variables
+
+The following environment variables are required:
+
+- `COMMIT_MESSAGE`: The commit message used when changes are available
+- `COMMIT_AUTHOR_EMAIL`: The Commit Authors Email Address
+- `COMMIT_AUTHOR_NAME`: The Commit Authors Name
+
+
+## Versioning
+
+We use [SemVer](http://semver.org/) for versioning. For the versions available, see the [tags on this repository](https://github.com/stefanzweifel/git-auto-commit-action/tags).
+
+## License
+
+This project is licensed under the MIT License - see the [LICENSE](https://github.com/stefanzweifel/git-auto-commit-action/blob/master/LICENSE) file for details.