It appears to be not possible to share a folder with a namespace. I get the following error from the API:
Cannot apply permission for a namespace ARN
The docs aren’t very clear on this, as CreateFolder links to
[ResourcePermission](https://docs.aws.amazon.com/quicksight/latest/APIReference/API_ResourcePermission.html) page, which states:
The ARN of an Amazon QuickSight user, group, or namespace associated with an analysis, dashboard, template, or theme. (This is common.)
How would you go about sharing a resource, e.g. a dashboard, with everyone in the account?