Sorry, there's no 'built-in' way to do that with the current version. You'd have to make some code changes to support a 'details' page.
You could do it without coding, but it would require a lot of manual steps
1. you'd have to create your 'detail' pages separately from the Repository as portal pages. So Add a new page to your portal, add an HTML/Text module and enter your article text/pictures. In the page settings, I believe there's a setting that will prevent the page from being included in the menu, so in effect it's a 'hidden' page.
2. then, modify the template.html file for the template you're using and change the javascript behind the 'read article' hyperlink to redirect you to the detail page when clicked. You could use the Description field to hold the URL of the details page.
That would allow you to use the Repository to organize your articles and provide a nice summary/listing of articles for your users, but still have full page rich-text articles. That should work fine as long as only you are creating the articles, it wouldn't work if you are intending for users to upload articles.
The next full release in April/May will support list and details views.