[FEATURE] -- 'Train' Feature in crewai Flow

[paarttipaabhalaji]

Feature Area

Core functionality

Is your feature request related to a an existing bug? Please link it here.

Not related to any existing bug.

Describe the solution you'd like

We can train the crew using crew().train(). How about training the flow which consist of 'n' of crews ?

If we have a option to train the flow, then its very easy of the developer to perform result tuning, end-to-end in a one go like flow().train()

Describe alternatives you've considered

No response

Additional context

No response

Willingness to Contribute

Yes, I'd be happy to submit a pull request