When a user clones a boilerplate repository, schema.json is not present. The Package metadat section of the Pulumi packages how-to-author page assumes the user knows what this file is, and perhaps unnecessarily describes some of its content. Some of our boilerplates for getting started with package authoring require creating this and modifying values in the JSOn file, others requires setting these fields in code.
It might be most helpful to move this documentation to the boilerplates, as each may have its own method of generating the schema?