add php cs fixer

.php-cs-fixer.dist.php

@@ -0,0 +1,18 @@
+<?php
+
+// define which files should be analyzed
+$finder = PhpCsFixer\Finder::create()
+    ->exclude(__DIR__ . '/site/plugins')
+    ->in(__DIR__ . '/site')
+;
+
+$config = new PhpCsFixer\Config();
+return $config
+    ->setRules(array(
+        '@PSR12' => true,
+        'array_syntax' => array('syntax' => 'long'),
+        'method_chaining_indentation' => true,
+    ))
+    ->setRiskyAllowed(true)
+    ->setFinder($finder)
+;