Add HateSpeech Corpus for Polish
@lhoestq Do you think using the ClassLabel is correct if we don't know the meaning of them? Once we find out the meanings we can still add them to the dataset card Feel free to ping me when the PR is ready for the final review
This PR adds a HateSpeech Corpus for Polish, containing offensive language examples.

- **Homepage:** http://zil.ipipan.waw.pl/HateSpeech
- **Paper:** http://www.qualitativesociologyreview.org/PL/Volume38/PSJ_13_2_Troszynski_Wawer.pdf