Based on the provided knowledge sources, there isn't specific information about configuring multiple namespaces files in the keto configuration. However, it's important to note that namespaces in Ory Keto are used to scope objects and subjects, and they contain rules that define which relationships are looked up as part of a permission check. In the Ory Permission Language, namespaces are defined as TypeScript classes. For example:

typescript import { Namespace, Context } from "@ory/keto-namespace-types"      class User implements Namespace {}   class Document implements Namespace {}   class Folder implements Namespace {}

Each namespace holds a set of permissions, which define which relationships are checked. For more detailed information on how to configure namespaces, you can refer to the [Ory Keto documentation](https://www.ory.sh/docs/keto/concepts/namespaces).