Add docs

README.md

@@ -1,2 +1,37 @@
-# action-yamllint
-GitHub Action - Yaml Lint
+# GitHub YAMLlint
+
+This action executes `yamllint` (https://github.com/adrienverge/yamllint) against file(s) or folder
+
+## Usage
+
+### Required parameters
+
+- `file_or_dir` - Enter file/folder (space speparated), wildcards accepted. Examples:
+    - `file1.yaml`
+    - `file1.yaml file2.yaml`
+    - `.` - run against all yaml files in current directory recursively
+    - `./**/*values.yaml` - run against all files that end with `values.yaml` recursively
+
+### Optional parameters
+
+- `config_file` - Path to custom configuration
+- `config_data` - Custom configuration (as YAML source)
+- `format` - Format for parsing output [parsable,standard]
+- `strict` - Return non-zero exit code on warnings as well as errors
+
+### Example usage in workflow
+
+```yaml
+name: Yaml Lint
+on: [push]
+jobs:
+  lintAllTheThings:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@master
+    - name: yaml-lint
+      uses: ibiqlik/action-yamllint@master
+      with:
+        file_or_dir: ./**/*val*.yaml
+        config_file: .yamllint.yml
+```