Broken Link to PubMed Abstracts dataset .
This has already been reported in the HF Course repo (https://github.com/huggingface/course/issues/623). @lhoestq @albertvillanova @lewtun I don't think we are allowed to host these data files on the Hub (due to DMCA), which means the only option is to use a different dataset in the course (and to re-record the video 🙂), no? Keeping the video is maybe fine, we can add a note on youtube to suggest to load a dataset with a different name. Maybe C4 ? And update the code snippets on the website ? Maybe you want to try it with the PUBMED dataset that I reproduced based on the The [PubMed Abstract GitHub Site](http://github.com/thoppe/The-Pile-PubMed) and uploaded on the HuggingFace:

```
from datasets import load_dataset
pubmed_dataset = load_dataset("hwang2006/PUBMED_title_abstracts_2020_baseline")
pubmed_dataset

#Downloading data: 100%
#7.98G/7.98G [11:47<00:00, 9.68MB/s]
#Generating train split: 17722096/0 [00:36<00:00, 505376.37 examples/s]

#DatasetDict({
#   train: Dataset({
#        features: ['meta', 'text'],
#        num_rows: 17722096
#    })
#})
```
### Describe the bug

The link provided for the dataset is broken,
data_files = 
[https://the-eye.eu/public/AI/pile_preliminary_components/PUBMED_title_abstracts_2019_baseline.jsonl.zst](url)

The 

### Steps to reproduce the bug

Steps to reproduce:

1) Head over to [https://huggingface.co/learn/nlp-course/chapter5/4?fw=pt#big-data-datasets-to-the-rescue](url)

2) In the Section  "What is the Pile?", you can see a code snippet that contains the broken link.

### Expected behavior

The link should Redirect to the  "PubMed Abstracts dataset" as expected .

### Environment info

.