added Rector config.

Author: DKravtsov

rector.php

@@ -0,0 +1,24 @@
+<?php
+
+declare(strict_types=1);
+
+use Rector\Config\RectorConfig;
+use Rector\Set\ValueObject\LevelSetList;
+use Rector\Symfony\Set\SymfonySetList;
+
+return static function (RectorConfig $rectorConfig): void {
+    $rectorConfig->paths([
+        __DIR__ . '/src',
+        __DIR__ . '/tests',
+    ]);
+
+    $rectorConfig->symfonyContainerXml(__DIR__ . '/var/cache/dev/App_KernelDevDebugContainer.xml');
+
+    // define sets of rules
+    $rectorConfig->sets([
+        LevelSetList::UP_TO_PHP_81,
+        SymfonySetList::SYMFONY_60,
+        SymfonySetList::SYMFONY_CODE_QUALITY,
+        SymfonySetList::SYMFONY_CONSTRUCTOR_INJECTION,
+    ]);
+};