adding cdt dataset
> Thanks for adding this one !
> 
> I left a few comments
> 
> after the change you'll need to regenerate the dataset_infos.json file as well

dataset_infos.json regenerated looks like this PR includes changes to many files other that the ones for CDT
could you create another branch and another PR please ?
- **Name:** *Cyberbullying Detection Task*
- **Description:** *The Cyberbullying Detection task was part of 2019 edition of PolEval competition. The goal is to predict if a given Twitter message contains a cyberbullying (harmful) content.*
- **Data:** *https://github.com/ptaszynski/cyberbullying-Polish*
- **Motivation:** *The KLEJ benchmark (Kompleksowa Lista Ewaluacji Językowych) is a set of nine evaluation tasks for the Polish language understanding.*