New flow step type: command -> command

[stefan-ka]

Current flow steps can be of the types:

• event EventXY triggers command CommandXY
• command CommandZ emits event EventZ

Do we maybe need another type?

• command CommandA triggers command CommandB

Could be useful, but is however not conform to Event Storming meta models such as the one from DDD crew:

[wylswz]

I think it's useful when there are immediate events which are trivial.
There also could be cases where one event triggers another, as described in this blog