- use CSS to add a border for each .news item (differentiate the first child and the remaining items. For instance, add a border top to all .news items and not for the first-child).
- create a template override of the module in your template and add the <hr> tag between items. Template overrides need to be checked after every module update therefore I would suggest not do it and stick with CSS for a maintenance-free solution.
Simplify Your Web is not affiliated with or endorsed by The Joomla! Project™ or Open Source Matters. The Joomla!® name and logo is used under a limited license granted by Open Source Matters the trademark holder in the United States and other countries.