Where you have categories on the side, and nested pages for different bits on the side.
I was looking for examples of somebody attempting something similar, but can’t find anything. Perhaps it’s not possible without nested CMS collections.
If that doesn’t suit what you need you can always use gitbook.com. It’s great and it’s free. I only say that because they have certain tools in there (like H1 & H2 Indexing for example among others) that you couldn’t do with Webflow currently. You can however still create a doc site with Webflow. I just don’t know exactly how extensive you need it, which would really be the determining factor.