Incorrect link for ChatML guide

In [Chapter 11 Section 2](https://huggingface.co/learn/llm-course/en/chapter11/2#base-models-vs-instruct-models), the link in the following line directs the user to a configuration item, not a guide:

> Here’s a guide on [ChatML](https://huggingface.co/HuggingFaceTB/SmolLM2-135M-Instruct/blob/e2c3f7557efbdec707ae3a336371d169783f1da1/tokenizer_config.json#L146)

This is also the same link used in the note just under it:
> For example, the `SmolLM2-135M-Instruct` model uses [this configuration](https://huggingface.co/HuggingFaceTB/SmolLM2-135M-Instruct/blob/e2c3f7557efbdec707ae3a336371d169783f1da1/tokenizer_config.json#L146).

I'm not sure of the intended destination, but it may be the [Chat Templating](https://huggingface.co/docs/transformers/main/chat_templating) guide.