Include new permission settings for macOS 10.15 (bug#37551)
* nextstep/templates/Info.plist.in (NSDesktopFolderUsageDescription): (NSDocumentsFolderUsageDescription): (NSDownloadsFolderUsageDescription): (NSRemovableVolumesUsageDescription): Add description to enable setting in macOS 10.15. Copyright-paperwork-exempt: yes