Add configuration example

Author: dmolineus

README.md

@@ -1,3 +1,22 @@
 # Rector plugin for phpcq
 
 This plugin provides [rector](https://github.com/rectorphp/rector) integration for phpcq.
+
+## Configuration
+
+Extend your `.phpcq.yaml.dist` configuration by adding the plugin and configuring the task:
+
+```yaml
+phpcq:
+  plugins:
+    version: ^1.0
+    signed: false
+
+tasks:
+  rector:
+    config:
+      # Set to 
+      dry-run: false 
+      # Custom config file, defaults to rector.php
+      config: custom-rector.php
+```