Basic Setup

1. In an existing VS solution, add a .net Class project. I suggest you call it DocFx Documentation, but you can name it anything you want. 
2. In that new project, install the nuget docfx.console
3. Rebuild the project once - you should get something in the _site folder. This isn't useful, but you know it's working. 
4. Delete the class1.cs file in the project - you don't need it.
5. Setup a local iis to point to this site folder - this is important, because the docs use a lot of JavaScript which only work if they are served from a real web server. 
   1. set it up
   2. if necessary, add the hosts entry so you can access it
   3. test it

Configure the docfx.json

Open the docfx.json in the root folder of the new project. You need to tell docfx