Update README.md

Author: bastianschwarz

README.md

@@ -1,2 +1,50 @@
 # workflows.php
 Default workflos for php projects
+
+## Available Workflows
+
+### CI
+
+Validates composer.json and runs the CI pipelines to verify the project is working correctly. The workflow supports building a matrix of php versions and stabilities. By default prefer-lowest and prefer-stable are tested with all given php versions which should cover most of the package ranges. 
+
+#### Inputs
+    php-versions:
+      description: 'The php versions to test as JSON array. Will be converted and used to create a matrix.'
+      default: '["8.1"]'
+      required: true
+      type: string
+    prefer-stability:
+      description: 'The staibility of the packages to use. Will be converted and used to create a matrix.'
+      default: '["prefer-lowest", "prefer-stable"]'
+      type: string
+    test-command:
+      description: 'The command to run for executing tests'
+      default: 'composer ci-all'
+      type: string
+
+#### Example
+
+```yaml
+
+name: CI
+
+on:
+  push:
+    branches:
+      - main
+      - release
+    paths-ignore:
+      - '**.md'
+  pull_request:
+    branches:
+      - main
+      - release
+    paths-ignore:
+      - '**.md'
+
+jobs:
+  ci:
+    uses: codenamephp/workflows.php/.github/workflows/ci.yml@main
+    with:
+      php-versions: '["8.1", "8.0"]'
+```