Update README.md

Author: 0test

README.md

@@ -16,6 +16,7 @@ $ composer require khanamiryan/qrcode-detector-decoder
 ## Usage 
 ```php
 require __DIR__ . "/vendor/autoload.php";
+use Zxing\QrReader;
 $qrcode = new QrReader('path/to_image');
 $text = $qrcode->text(); //return decoded text from QR Code
 ```