Prerequisites of "Preparing your computing environment for GDK" are confusing and missing critical information

Problem

The prerequisites of the Preparing your computing environment for GDK document are confusing in that some items are stated as prerequisites, but the text then states instructions for the prerequisites are covered in the text. In those instances, they are not prerequisites. A Ruby package manager is stated as being a prerequisite, but no instructions on installing either Ruby or a Ruby package manager, are included or referenced. Without this prerequisite, the other instructions cannot be completed.

Scope

"Preparing your computing environment for GDK" document only.

Suggestions

1. Refine the prerequisites into a list of actual prerequisites.
2. Add an introduction which states the purpose of the instructions, and the expected outcome.
3. Review the prerequisites, verifying that instructions for each are either included or referenced within the document.