Author: Urs Format: MarkdownItexfixed the pdf-link, and hyperlinked the second author name
<a href="https://ncatlab.org/nlab/revision/diff/Homotopy+theories+and+model+categories/2">diff</a>, <a href="https://ncatlab.org/nlab/revision/Homotopy+theories+and+model+categories/2">v2</a>, <a href="https://ncatlab.org/nlab/show/Homotopy+theories+and+model+categories">current</a>
fixed the pdf-link, and hyperlinked the second author name