<PackageReference Include="System.Configuration.ConfigurationManager" Version="11.0.0-preview.2.26159.112" />

System.Configuration.SettingsGroupDescriptionAttribute

Provides a string that describes an application settings property group. This class cannot be inherited.
namespace System.Configuration { public sealed class SettingsGroupDescriptionAttribute : Attribute { public string Description { get; } public SettingsGroupDescriptionAttribute(string description); } }