The documentation uses a custom, internal ERP.net version of DocFX to build: https://github.com/ErpNetDocs/docfx
The entities, attributes and front-end business rules are managed automatically from internal entity meta-data. There is a build each night, which updates the entity topics with the latest changes.
The model includes the very latest updates from the night builds.
Some attributes might not exist in your current version of ERP.net.
The business rules and generation procedures are added manually.