Update the Spectre.Console.Cli documentation with CancellationToken

Now that #1911 is merged, all `Execute` methods of commands have a new CancellationToken parameter. Update the documentation to reflect that.

New documentation shall still be written with an example on how to pass the top-level CancellationToken to the app.Run(Async) method.

docs/input/cli/commands.md

@@ -18,7 +18,7 @@ public class HelloCommand : Command<HelloCommand.Settings>
     }
 
 
-    public override int Execute(CommandContext context, Settings settings)
+    public override int Execute(CommandContext context, Settings settings, CancellationToken cancellationToken)
     {
         AnsiConsole.MarkupLine($"Hello, [blue]{settings.Name}[/]");
         return 0;

docs/input/cli/composing.md

@@ -55,7 +55,7 @@ in the previous step.
 ```csharp
 public class AddPackageCommand : Command<AddPackageSettings>
 {
-    public override int Execute(CommandContext context, AddPackageSettings settings)
+    public override int Execute(CommandContext context, AddPackageSettings settings, CancellationToken cancellationToken)
     {
         // Omitted
         return 0;
@@ -64,7 +64,7 @@ public class AddPackageCommand : Command<AddPackageSettings>
 
 public class AddReferenceCommand : Command<AddReferenceSettings>
 {
-    public override int Execute(CommandContext context, AddReferenceSettings settings)
+    public override int Execute(CommandContext context, AddReferenceSettings settings, CancellationToken cancellationToken)
     {
         // Omitted
         return 0;

docs/input/cli/getting-started.md

@@ -33,7 +33,7 @@ internal sealed class FileSizeCommand : Command<FileSizeCommand.Settings>
         public bool IncludeHidden { get; init; }
     }
 
-    public override int Execute([NotNull] CommandContext context, [NotNull] Settings settings)
+    public override int Execute(CommandContext context, Settings settings, CancellationToken cancellationToken)
     {
         var searchOptions = new EnumerationOptions
         {

docs/input/cli/introduction.md

@@ -61,7 +61,7 @@ in the previous step.
 ```csharp
 public class AddPackageCommand : Command<AddPackageSettings>
 {
-    public override int Execute(CommandContext context, AddPackageSettings settings)
+    public override int Execute(CommandContext context, AddPackageSettings settings, CancellationToken cancellationToken)
     {
         // Omitted
         return 0;
@@ -70,7 +70,7 @@ public class AddPackageCommand : Command<AddPackageSettings>
 
 public class AddReferenceCommand : Command<AddReferenceSettings>
 {
-    public override int Execute(CommandContext context, AddReferenceSettings settings)
+    public override int Execute(CommandContext context, AddReferenceSettings settings, CancellationToken cancellationToken)
     {
         // Omitted
         return 0;

docs/input/cli/unit-testing.md

@@ -40,7 +40,7 @@ The following example validates the exit code and terminal output of a `Spectre.
             _console = console;
         }
 
-        public override int Execute(CommandContext context)
+        public override int Execute(CommandContext context, CancellationToken cancellationToken)
         {
             _console.WriteLine("Hello world.");
             return 0;
@@ -78,7 +78,7 @@ public sealed class InteractiveCommandTests
             _console = console;
         }
 
-        public override int Execute(CommandContext context)
+        public override int Execute(CommandContext context, CancellationToken cancellationToken)
         {
             var fruits = _console.Prompt(
                 new MultiSelectionPrompt<string>()