Aded new readme

README.md

@@ -2,6 +2,42 @@
 
 Yii2 edition of the [audittrail extension](https://github.com/Sammaye/audittrail).
 
+## How to use
+
+To use this extension you can simply add it to the model's behaviours:
+
+	use yii\db\ActiveRecord;
+
+	class Model extends ActiveRecord
+	{
+		public function behaviors()
+		{
+			return [
+				'sammaye\audittrail\LoggableBehaviour'
+			];
+		}
+	}
+
+You can convert the entered behaviour into a key - value structure to define options for the extension for that model:
+
+	class Model extends ActiveRecord
+	{
+		public function behaviors()
+		{
+			return [
+				'LoggableBehaviour' => [
+					'class' => 'sammaye\audittrail\LoggableBehaviour',
+					'ignored' => ['some_field'], // This ignores fields from a selection of all fields, not needed with allowed
+					'allowed' => ['another_field'] // optional, not needed if you use ignore
+				]
+			];
+		}
+	}
+
+And that is basically how to setup this extension.
+
+## Changes
+
 There are a couple of changes.
 
 One of them is how to define global parameters for this extension.
@@ -100,7 +136,11 @@ Currently in this extension I store the fully qualified name of the class to:
 
 ## Migration
 
-You may need to copy the migration file (within the `migrations` folder) to your `console/migrations` folder since Yii2 may not recognise it exists otherwise.
+There are two ways of doing this:
+
+- Copy the migration file (within the `migrations` folder) to your `console/migrations` folder
+- Use `--migrationPath` option of the `migrate` command to 
+[point to the migrations folder in this repo](http://www.yiiframework.com/doc-2.0/guide-db-migrations.html#migrating-multiple-databases)
 
 ## Resources