When exporting as a website, is there supposed to be an index.html page created that has a link to everything? I’ve exported several folders and I don’t see the index file or a way to “enter” the website.
File > Export > as Website isn’t well documented, IMO. The action does not create an index file, but the script here will. As Christian mentions in the linked post, if you have activated DEVONthink > Preferences > Editing > WikiLinks > Automatic > Names and Aliases then the script will create a usable index file. Also, if you have WikiLinks activated, and the linked-to files are part of your export, then those WikiLinks will remain active in the exported files and can be used to navigate from one file to another without an index. IOW, you can build your own wiki with this feature.
The DEVONthink Pro Office manual on page 142 mentions the types of documents that can be exported:
You can also export images, but need to reference them as a WikiLink in one of the exported rich text or plain text files. Note that WikiLinks do not work in sheets, and exported sheets will not have active links. You can also create your own export templates, with CSS, Javascript, etc., and keep them in ~/Library/Application Support/DEVONthink Pro/Websites/