Show help text on demand (#49)

CliFx.Tests.Dummy/Commands/ShowHelpTextOnErrorCommand.cs

@@ -0,0 +1,18 @@
+using CliFx.Attributes;
+using CliFx.Exceptions;
+using System.Threading.Tasks;
+
+namespace CliFx.Tests.Dummy.Commands
+{
+    /// <summary>
+    /// Demos how to show help text from an organizational command.
+    /// </summary>
+    [Command("cmd", Description = "This is an organizational command. " +
+        "I don't do anything except provide a route to my subcommands. " +
+        "If you use just me, I print the help text to remind you of my subcommands.")]
+    public class ShowHelpTextOnCommandExceptionCommand : ICommand
+    {
+        public ValueTask ExecuteAsync(IConsole console) =>
+            throw new CommandException(null, showHelp: false);
+    }
+}