The documentation for the Blender glTF 2.0 exporter is separated into two main sections.
User Documentation
One for the Blender user, who wants to export a Blender scene to the glTF 2.0 format.
The purpose of the section is for understanding the usage of the exporter.
Developer Documentation
The other for developers, who want to do bug fixes and/or extend the exporter.
This section is mainly for developers, who need to understand the source of the exporter.