Option to have the document navigation panel closed by default in Resources

When a member opens a document in a Resource, the navigation panel beside it opens by default and lists the other documents in the same folder. Today the panel only hides itself, for members, when the Resource holds a single document, so an admin who links members straight to one document has to restructure into one Resource per document to stop the others showing.

Request: a setting, per Resource or community-wide, to have the navigation panel start closed (or be hidden) when a document opens, so admins can send members to a single document without restructuring their Resources.