Docs: Add a changelog entry for the addition of 'wp-admin', 'wp-content', and 'wp-includes' as reserved names for the `subdirectory_reserved_names` filter docs.

The new names were introduced in [33952].

See #33615. See #32246.


git-svn-id: https://develop.svn.wordpress.org/trunk@34235 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/ms-functions.php

@@ -619,6 +619,7 @@ function wpmu_validate_blog_signup( $blogname, $blog_title, $user = '' ) {
 			 * Filter reserved site names on a sub-directory Multisite install.
 			 *
 			 * @since 3.0.0
+			 * @since 4.4.0 'wp-admin', 'wp-content', and 'wp-includes' were added to the reserved names list.
 			 *
 			 * @param array $subdirectory_reserved_names Array of reserved names.
 			 */