added path when script is run from yii2-dev/extensions

extensions/apidoc/apidoc

@@ -13,6 +13,7 @@ defined('YII_DEBUG') or define('YII_DEBUG', false);
 $composerAutoload = [
 	__DIR__ . '/vendor/autoload.php', // standalone with "composer install" run
 	__DIR__ . '/../../autoload.php', // script is installed as a composer binary
+    __DIR__ . '/../../../../autoload.php', // script is run from yii2-dev/extensions
 ];
 $vendorPath = null;
 foreach ($composerAutoload as $autoload) {