add info on TRL docs (#27024)

* add info on TRL docs

* add TRL link

* tweak text

* tweak text

docs/source/en/main_classes/trainer.md

@@ -18,6 +18,12 @@ rendered properly in your Markdown viewer.
 
 The [`Trainer`] class provides an API for feature-complete training in PyTorch for most standard use cases. It's used in most of the [example scripts](https://github.com/huggingface/transformers/tree/main/examples).
 
+<Tip>
+
+If you're looking to fine-tune a language model like Llama-2 or Mistral on a text dataset using autoregressive techniques, consider using [`trl`](https://github.com/huggingface/trl)'s [`~trl.SFTTrainer`]. The [`~trl.SFTTrainer`] wraps the [`Trainer`] and is specially optimized for this particular task and supports sequence packing, LoRA, quantization, and DeepSpeed for efficient scaling to any model size. On the other hand, the [`Trainer`] is a more versatile option, suitable for a broader spectrum of tasks.
+
+</Tip>
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 Before instantiating your [`Trainer`], create a [`TrainingArguments`] to access all the points of customization during training.
 
 The API supports distributed training on multiple GPUs/TPUs, mixed precision through [NVIDIA Apex](https://github.com/NVIDIA/apex) and Native AMP for PyTorch.