Fix #384: Add multi curl file upload example

examples/multi_curl_upload_file.php

@@ -0,0 +1,25 @@
+<?php
+require __DIR__ . '/vendor/autoload.php';
+
+use \Curl\MultiCurl;
+
+$multi_curl = new MultiCurl();
+
+// HINT: If API documentation refers to using something like curl -F "myimage=image.png",
+// curl --form "myimage=image.png", or the html form is similar to <form enctype="multipart/form-data" method="post">,
+// then try uncommenting the following line:
+// $multi_curl->setHeader('Content-Type', 'multipart/form-data');
+
+$multi_curl->addPost('https://httpbin.org/post', array(
+    'image' => new CURLFile('the-lorax.jpg'),
+));
+
+$multi_curl->addPost('https://httpbin.org/post', array(
+    'image' => new CURLFile('swomee-swans.jpg'),
+));
+
+$multi_curl->addPost('https://httpbin.org/post', array(
+    'image' => new CURLFile('truffula-trees.jpg'),
+));
+
+$multi_curl->start();