Enable file save in render method (#21)

* Enable file save in render method

* delete extra semicolon

* Simplify method's params

src/GenerateQrCode.php

@@ -68,12 +68,13 @@ public function toBase64(): string
      * Render the QR code as base64 data image.
      *
      * @param  array  $options  The list of options for QROption (https://github.com/chillerlan/php-qrcode)
+     * @param  string|null  $file  File string represent file path,name and extension
      *
      * @return string
      */
-    public function render(array $options = []): string
+    public function render(array $options = [], string $file = null): string
     {
         $options = new QROptions($options);
-        return (new QRCode($options))->render($this->toBase64());
+        return (new QRCode($options))->render($this->toBase64(), $file);
     }
 }