I was being lazy when I quickly threw this together for a specific request.
To add something, add another placeholder to the template, such as
<div class="randItem">
<h3 class="randLink"><a href="[~[+id+]~]">[+title+]</a></h3>
<p>[+summary+]</p>
</div>
then add these lines after line 39:
$items .= str_replace('[+id+]',$resource[$item]['id'],$tpl);
$items .= str_replace('[+title+]',$resource[$item]['pagetitle'],$tpl);
It needs to be rewritten to allow for an arbitrary number of placeholders, at least.