Creates a shortcode to display the date/time when a post/page was last updated (with optional formatting).
[lastupdated] shortcode to display the date and/or time of the last update to a post or page. If used without any arguments, it will display the date in the format configured in the Settings > General tab. It supports several optional arguments: format, before, and after. These options allow you to change how the date/time is formatted and if anything should appear before or after the date/time is displayed.