add pref_train_gpu_one.mdx
See issue #17459
Good evening.
I didn't translate technical terms and I preferred to keep them in english. So I hope it's all ok.
I had some problems in previous pull requests; if it fails again, please can you say how to resolve?
Good bye.

The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/transformers/pr_22926). All of your documentation changes will be reflected on that endpoint.