public static function append(array $config = [])
    {
        self::$config = self::mergeConfigs(self::$config, $config);

        if (isset(self::$config['paths']['output'])) {
            self::$outputDir = self::$config['paths']['output'];
        }
        if (isset(self::$config['paths']['data'])) {
            self::$dataDir = self::$config['paths']['data'];
        }
        if (isset(self::$config['paths']['support'])) {
            self::$supportDir = self::$config['paths']['support'];
        }
        if (isset(self::$config['paths']['tests'])) {
            self::$testsDir = self::$config['paths']['tests'];
        }

        return self::$config;
    }