Add possibility to set description and/or data for the default command (#1091)

src/Spectre.Console.Cli/Internal/Configuration/Configurator.cs

@@ -25,11 +25,12 @@ internal sealed class Configurator : IUnsafeConfigurator, IConfigurator, IConfig
         Examples.Add(args);
     }
 
-    public void SetDefaultCommand<TDefaultCommand>()
+    public ConfiguredCommand SetDefaultCommand<TDefaultCommand>()
         where TDefaultCommand : class, ICommand
     {
         DefaultCommand = ConfiguredCommand.FromType<TDefaultCommand>(
             CliConstants.DefaultCommandName, isDefaultCommand: true);
+        return DefaultCommand;
     }
 
     public ICommandConfigurator AddCommand<TCommand>(string name)

src/Spectre.Console.Cli/Internal/Configuration/DefaultCommandConfigurator.cs

@@ -0,0 +1,36 @@
+namespace Spectre.Console.Cli.Internal.Configuration;
+
+/// <summary>
+/// Fluent configurator for the default command.
+/// </summary>
+public sealed class DefaultCommandConfigurator
+{
+    private readonly ConfiguredCommand _defaultCommand;
+
+    internal DefaultCommandConfigurator(ConfiguredCommand defaultCommand)
+    {
+        _defaultCommand = defaultCommand;
+    }
+
+    /// <summary>
+    /// Sets the description of the default command.
+    /// </summary>
+    /// <param name="description">The default command description.</param>
+    /// <returns>The same <see cref="DefaultCommandConfigurator"/> instance so that multiple calls can be chained.</returns>
+    public DefaultCommandConfigurator WithDescription(string description)
+    {
+        _defaultCommand.Description = description;
+        return this;
+    }
+
+    /// <summary>
+    /// Sets data that will be passed to the command via the <see cref="CommandContext"/>.
+    /// </summary>
+    /// <param name="data">The data to pass to the default command.</param>
+    /// <returns>The same <see cref="DefaultCommandConfigurator"/> instance so that multiple calls can be chained.</returns>
+    public DefaultCommandConfigurator WithData(object data)
+    {
+        _defaultCommand.Data = data;
+        return this;
+    }
+}