Add a changelog entry to the DocBlock for `comment_form()` for the `class_submit` argument added in 4.1.

See [29809]. See #20446.


git-svn-id: https://develop.svn.wordpress.org/trunk@31803 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/comment-template.php

@@ -2153,6 +2153,7 @@ function wp_list_comments( $args = array(), $comments = null ) {
  * in the array of fields.
  *
  * @since 3.0.0
+ * @since 4.1.0 Introduced the 'class_submit' argument.
  * @since 4.2.0 Introduced 'submit_button' and 'submit_fields' arguments.
  *
  * @param array       $args {