Broken Link to PubMed Abstracts dataset .
### 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

.