Document complex object binding

I've been creating all of my handlers according to the documentation like this:

```csharp
command.Handler = CommandHandler.Create((IEnumerable include, int count) =>
{
var request = new SchemaRollbackRequest(include, count);

var svc = Container.ResolveService();

svc.RollbackSchema(request);
});
```

and it's a huge pain to update the args for every new option (requires multiple updates).

i just started creating a new command that required more than 7 options and stumbled across #458 where it's discussed to bind to a complex object, which fits my use case perfectly.

can documentation be added around the complex object binding?