Which are the states including the common SFN states for which <state>.output () can be applied ?

This is a separate issue created from the discussion by @nsankar addressed to @wong-a from the issue id #31
The key point is which are the common SFN and AWS specific service states where we can use the form `.output()` in this SDK. Please include it in the documentation.

More details and an example state using output() is as under.,

(1) Which are the states including the common SFN states for which state output () is applicable **or** can be used? This is not in the document unless we see an example, for instance, as an example output () is applicable to the processing step which can be then used in a choice state as cited below:

```
processing_step = ProcessingStep(
"SageMaker processing step",
processor=script_processor,
job_name=execution_input["PreprocessingJobName"], ## placeholder per schema above. Later in workflow execute() below pass the uuid of jobname
inputs=inputs,
outputs=outputs,
# container_arguments=["--train-test-split-ratio", "0.2"],
container_entrypoint=["python3", "/opt/ml/processing/input/code/myprogram.py"],
)

choice_state1.add_choice(ChoiceRule.StringEquals(processing_step**.output()**["ProcessingJobStatus"], "Completed"), lambda_state1)

```

El issue menciona ProcessingStep, ChoiceRule.StringEquals y la salida de estado output(), pero no identifica ningún archivo de documentación ni ninguna prueba. Empieza localizando la documentación del SDK sobre los estados de workflow y el ejemplo de ProcessingStep; después, determina qué estados comunes y específicos de AWS admiten output(). Se considera completado cuando la documentación enumera los estados aplicables e incluye un ejemplo funcional.

Escrito por el modelo de indexación a partir del texto del issue.