text: Title: [BUG] dataset link is broken
  Body: I try to run the example [here](https://unit8co.github.io/darts/examples/14-transfer-learning.html) but the dataset link is broken. May you fix the link? Thank you!
  
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  !curl -L https://github.com/unit8co/amld2022-forecasting-and-metalearning/blob/main/data/m3_dataset.xls\?raw\=true -o m3_dataset.xls
  !curl -L https://github.com/unit8co/amld2022-forecasting-and-metalearning/blob/main/data/passengers.pkl\?raw\=true -o passengers.pkl
  !curl -L https://github.com/unit8co/amld2022-forecasting-and-metalearning/blob/main/data/m4_monthly_scaled.pkl\?raw\=true -o m4_monthly_scaled.pkl
  ~~~~