v1.2 added docs for catalog hidden_models

[svetoslavpetkov]

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[diannewood]

I agree with Stanislav's comments. Otherwise it looks good.

[diannewood]

I just watched the videos (thank you for including them!) and think we should add something about how this feature is used. How about:

Use case: When deploying a composite model the referenced component models may not need to be accessible as separate models.

[svetoslavpetkov]

I have read the CLA Document and I hereby sign the CLA

[svetoslavpetkov]

I have read the CLA Document and I hereby sign the CLA