Docs: Adjust wp_is_json_request() and wp_is_xml_request() return value descriptions for consistency.

See #48771, #48303.
Built from https://develop.svn.wordpress.org/trunk@46760


git-svn-id: http://core.svn.wordpress.org/trunk@46560 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/load.php

@@ -1478,7 +1478,8 @@ function wp_finalize_scraping_edited_file_errors( $scrape_key ) {
  *
  * @since 5.0.0
  *
- * @return bool True if Accepts or Content-Type headers contain application/json, false otherwise.
+ * @return bool True if `Accepts` or `Content-Type` headers contain `application/json`.
+ *              False otherwise.
  */
 function wp_is_json_request() {
 
@@ -1527,7 +1528,8 @@ function wp_is_jsonp_request() {
  *
  * @since 5.2.0
  *
- * @return bool True if `Accepts` or `Content-Type` headers contain XML, false otherwise.
+ * @return bool True if `Accepts` or `Content-Type` headers contain `text/xml`
+ *              or one of the related MIME types. False otherwise.
  */
 function wp_is_xml_request() {
 	$accepted = array(