Docs: Add missing @return tag for WP_Automatic_Updater::is_disabled().

Follow-up to [25421], [25823], [25859].

Props sakibmd, jrf, patelmohip, akmelias.
See #57680.

git-svn-id: https://develop.svn.wordpress.org/trunk@55594 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-admin/includes/class-wp-automatic-updater.php

@@ -27,6 +27,8 @@ class WP_Automatic_Updater {
 	 * Determines whether the entire automatic updater is disabled.
 	 *
 	 * @since 3.7.0
+	 *
+	 * @return bool True if the automatic updater is disabled, false otherwise.
 	 */
 	public function is_disabled() {
 		// Background updates are disabled if you don't want file changes.