You can create docks by choosing a folder using the "Import Dock" item in the File menu. DragThing will then create a new dock and add all the items in that folder to the dock automatically. If you export the dock, DragThing will create a folder and save all the dock items as Finder alias files, with each layer of the dock in a different sub-folder.
You can also select a text file containing HTML, and DragThing will extract all the URLs from the HTML with their titles, and create a dock for them. This is especially useful with things like your bookmarks file from your web browser, which is usually stored as HTML. You can export a dock of URLs to create a new HTML file you can open in your web browser.
If you have a dock with both URLs and normal dock items that you export, DragThing will create an HTML file for all the URLs inside the folder containing the alias files.