[DOC] Document Adding New Backbone

[mtanco]

📃 Documentation

How to add a custom backbone from Hugging Face that is not in the recommended dropdown list to Step 5 of configuring parameters: https://docs.h2o.ai/h2o-llmstudio/guide/experiments/create-an-experiment

Motivation

We mention this is supported, but we do not tell users how to do it.

[pascal-pfeiffer]

It is a dropdown that also allows for free typing. So any model from huggingface can just be copy pasted in there. I agree this isn't very intuitive for first time users. Any idea how to make it more obvious what is possible there?

[pascal-pfeiffer]

backbone-2024-06-28_21.17.58.mp4