fix config doc

Author: samsonasik

README.md

@@ -89,7 +89,7 @@ return [
     'doctrine' => [
         'connection' => [
             'orm_default' => [
-                'driverClass' => 'Doctrine\DBAL\Driver\PDO\MySql\Driver,
+                'driverClass' => 'Doctrine\DBAL\Driver\PDO\MySql\Driver',
                 'params' => [
                     'user'     => 'mysqluser',
                     'password' => 'mysqlpassword',