Docs: Add a missing file header to wp-includes/class-wp-http-streams.php, introduced in [33748].

Also clarifies the class DocBlock summary for `WP_Http_Streams` to better describe its purpose.

See #33413. See #33701.


git-svn-id: https://develop.svn.wordpress.org/trunk@33878 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/class-wp-http-streams.php

@@ -1,9 +1,17 @@
 <?php
 /**
- * HTTP request method uses PHP Streams to retrieve the url.
+ * HTTP API: WP_Http_Streams object class
+ *
+ * @package WordPress
+ * @subpackage HTTP
+ * @since 4.4.0
+ */
+
+/**
+ * Core class used to integrate PHP Streams as an HTTP transport.
  *
  * @since 2.7.0
- * @since 3.7.0 Combined with the fsockopen transport and switched to stream_socket_client().
+ * @since 3.7.0 Combined with the fsockopen transport and switched to `stream_socket_client()`.
  */
 class WP_Http_Streams {
 	/**