This directory includes template files for Nginx to support friendly URLs and FastCGI cache for WordPress. You may use them in Custom HTTPd Configuration to include any of these for the domains you'd like to. We also plan to introduce user-level selection for multiple CMS (including WordPress+FastCGI cache) in a new Pro Pack add-on we are introducing; that way users could simply do this in a single click, and DirectAdmin will take care of everything else.
It's still in early development but docs will be coming soon.