Add CC-News dataset of English language articles
@vblagoje nice work, please add the README.md file and it would be ready @lhoestq @tanmoyio @yjernite please have a look at the dataset card. Don't forget that the dataset is still hosted on my private gs bucket and should eventually be moved to the HF bucket I will move the files soon and ping you when it's done and with the new URLs :)  Hi !

I just moved the file to a HF bucket. It's available at https://storage.googleapis.com/huggingface-nlp/datasets/cc_news/cc_news.tar.gz

Sorry for the delay ^^' @lhoestq no worries, updated PR with the new URL and rebased to master

Adds [CC-News](https://commoncrawl.org/2016/10/news-dataset-available/) dataset. It contains 708241 English language news articles. Although each article has a language field these tags are not reliable. I've used Spacy language detection [pipeline](https://spacy.io/universe/project/spacy-langdetect) to confirm that the article language is indeed English. 

The prepared dataset is temporarily hosted on my private Google Storage [bucket](https://storage.googleapis.com/hf_datasets/cc_news.tar.gz). We can move it to HF storage and update this PR before merging. 