Added the dataset clickbait_news_bg
Hi @tsvm  Great work! 
Since you have raised a clean PR could you close the earlier one -   #1445 ? 
 > Hi @tsvm Great work!
> Since you have raised a clean PR could you close the earlier one - #1445 ?

Done.
There was a problem with my [previous PR 1445](https://github.com/huggingface/datasets/pull/1445) after rebasing, so I'm copying the dataset code into a new branch and submitting a new PR.