Other options include but are not limited to providing minimal, low effort examples, high-level overview, linking to projects using these features, linking to relevant tests, commits, or source code, setting up an official community wiki and encouraging people to contribute.
Where does a beginner go to learn how to use the package manager these days? It looks like they still won't find any clues in the "Learn" section of Zig's website.
There's a promising page titled "Zig Build System" in there which references a "Package Management" section, but when you click on it, it doesn't exist!
But to answer your question, it exists in the comments of the auto-generated build.zig.zon file