update documentation (#11)

fixes #3

README.md

@@ -1,3 +1,66 @@
-# Rubocop GitHub Action
+![rubocop linter actions banner](screenshots/rubocop-linter-action.png)
 
-TODO
+# Rubocop Linter Action
+
+![version number](https://img.shields.io/static/v1?label=Version&message=v0.1.1&color=blue)
+
+GitHub Action to run Rubocop against your code.
+
+## Usage
+
+Add the following to your GitHub action workflow:
+
+```yaml
+- name: Rubocop Linter
+  uses: andrewmcodes/rubocop-linter-action@0.1.1
+  env:
+    GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+```
+
+## Example Workflow
+
+```yaml
+name: Ruby
+
+on: [push]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v1
+    - name: Set up Ruby 2.6
+      uses: actions/setup-ruby@v1
+      with:
+        ruby-version: 2.6.x
+    - name: add PostgreSQL dependencies
+      run: |
+        sudo apt-get update
+        sudo apt-get install -y postgresql-client libpq-dev
+    - name: Rubocop Linter
+      uses: andrewmcodes/rubocop-linter-action@0.1.1
+      env:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+```
+
+## Screenshots
+
+![example GitHub Action UI](screenshots/ui-example.png)
+
+## Contributing
+
+[Contributing Guide](/CONTRIBUTING.md)
+
+## Code of Conduct
+
+[Code of Conduct](/CODE_OF_CONDUCT.md)
+
+## License
+
+[MIT](/LICENSE.md)
+
+## Recognition
+
+This project was originally forked from [gimenete/rubocop-action](https://github.com/gimenete/rubocop-action). Many thanks to [Alberto Gimeno](https://github.com/gimenete) for creating this project.