Now looking at it, it is the same page and version.
Unfortunately it's just badly worded, the HMI application is only used for legacy projects. "Web Site Definitions" is a specific feature which has been completely remade, and as such are not necessary in the new integrated HMI.
If you have a look at the tutorial I have linked above it has a simple step-by-step guide for creating an HMI from scratch in the latest version.
I will get in touch with our documentation team to see if they can help you further.