docs: improve CURLRequest sample code

user_guide_src/source/libraries/curlrequest.rst

@@ -260,7 +260,7 @@ if it's not already set:
 
 .. literalinclude:: curlrequest/024.php
 
-.. note:: ``form_params`` cannot be used with the ``multipart`` option. You will need to use one or the other.
+.. note:: ``form_params`` cannot be used with the `multipart`_ option. You will need to use one or the other.
         Use ``form_params`` for ``application/x-www-form-urlencoded`` request, and ``multipart`` for ``multipart/form-data``
         requests.
 
@@ -306,13 +306,15 @@ multipart
 =========
 
 When you need to send files and other data via a POST request, you can use the ``multipart`` option, along with
-the `CURLFile Class <https://www.php.net/manual/en/class.curlfile.php>`_. The values should be an associative array
-of POST data to send. For safer usage, the legacy method of uploading files by prefixing their name with an `@`
+the `CURLFile Class <https://www.php.net/manual/en/class.curlfile.php>`_.
+
+The values should be an associative array
+of POST data to send. For safer usage, the legacy method of uploading files by prefixing their name with an ``@``
 has been disabled. Any files that you want to send must be passed as instances of CURLFile:
 
 .. literalinclude:: curlrequest/028.php
 
-.. note:: ``multipart`` cannot be used with the ``form_params`` option. You can only use one or the other. Use
+.. note:: ``multipart`` cannot be used with the `form_params`_ option. You can only use one or the other. Use
         ``form_params`` for ``application/x-www-form-urlencoded`` requests, and ``multipart`` for ``multipart/form-data``
         requests.
 

user_guide_src/source/libraries/curlrequest/028.php

@@ -1,6 +1,8 @@
 <?php
 
-$post_data = [
-    'foo'      => 'bar',
-    'userfile' => new \CURLFile('/path/to/file.txt'),
-];
+$client->request('POST', '/post', [
+    'multipart' => [
+        'foo'      => 'bar',
+        'userfile' => new \CURLFile('/path/to/file.txt'),
+    ],
+]);