Deployment example

[awaelchli]

It's not clear to users how they would take a trained LitGPT model and deploy it. There are of course 100 ways to do that but maybe we could have one standard example.

We have a conversion tutorial here
https://github.com/Lightning-AI/litgpt/blob/main/tutorials/convert_lit_models.md#a-finetuning-and-conversion-tutorial
but it stops there. We also have several Studios but it's not clear which one to use as a template.

[rasbt]

I'll try to expand on that, maybe it could be based on LitServe

[rasbt]

This was addressed in #1299