Update MultiCurl::addDownload() example

Author: zachborboa

examples/multi_curl_download.php

@@ -6,6 +6,6 @@
 use \Curl\MultiCurl;
 
 $multi_curl = new MultiCurl();
-$multi_curl->download('https://php.net/images/logos/php-med-trans.png', '/tmp/php-med-trans.png');
-$multi_curl->download('https://upload.wikimedia.org/wikipedia/commons/c/c1/PHP_Logo.png', '/tmp/PHP_Logo.png');
+$multi_curl->addDownload('https://php.net/images/logos/php-med-trans.png', '/tmp/php-med-trans.png');
+$multi_curl->addDownload('https://upload.wikimedia.org/wikipedia/commons/c/c1/PHP_Logo.png', '/tmp/PHP_Logo.png');
 $multi_curl->start();