在 icloud drive中显示 app的icloud文件夹

<key>NSUbiquitousContainers</key>
    <dict>
        <key>iCloud.com.example.app</key>
        <dict>
            <key>NSUbiquitousContainerIsDocumentScopePublic</key>
            <true/>
            <key>NSUbiquitousContainerName</key>
            <string>App name to display in iCloud Drive</string>
            <key>NSUbiquitousContainerSupportedFolderLevels</key>
            <string>None</string>
        </dict>
    </dict>