[Task] Example for Debugging Merlin Models

[bschifferer]

Description

I want to propose an example, how to debug merlin model architectures and functionality.

Content could be (not limited to it):

• viewing model.layers, explaining the structure
• generating a batch with next(iter(dataloader)) and calling individual model components (e.g. input block, parallel block, etc.)
• can we visualize merlin models with Tensorboard?

[rnyak]

related task https://github.com/NVIDIA-Merlin/models/issues/642