Docs: Document the return value of `get_settings_errors()` using hash notation.

Props stevenlinx, webdevmattcrom, atachibana.
Fixes #42786.

git-svn-id: https://develop.svn.wordpress.org/trunk@48760 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/includes/template.php

@@ -1797,7 +1797,16 @@ function add_settings_error( $setting, $code, $message, $type = 'error' ) {
  *
  * @param string $setting  Optional. Slug title of a specific setting whose errors you want.
  * @param bool   $sanitize Optional. Whether to re-sanitize the setting value before returning errors.
- * @return array Array of settings errors.
+ * @return array {
+ *     Array of settings errors.
+ *
+ *     @type string $setting Slug title of the setting to which this error applies.
+ *     @type string $code    Slug-name to identify the error. Used as part of 'id' attribute in HTML output.
+ *     @type string $message The formatted message text to display to the user (will be shown inside styled
+ *                           `<div>` and `<p>` tags).
+ *     @type string $type    Optional. Message type, controls HTML class. Possible values include 'error',
+ *                           'success', 'warning', 'info'. Default 'error'.
+ * }
  */
 function get_settings_errors( $setting = '', $sanitize = false ) {
 	global $wp_settings_errors;