Making the Hub the place for datasets in Portuguese

Let's make Hugging Face Datasets the central hub for datasets in Portuguese :)

**Motivation**. Datasets are currently quite scattered and an open-source central point such as the Hugging Face Hub would be ideal to support the growth of the Portuguese speaking community.

What are some datasets in Portuguese worth integrating into the Hugging Face hub?

Special thanks to @augusnunes for his collaboration on identifying the first ones:

- [NILC - USP](http://www.nilc.icmc.usp.br/nilc/index.php/tools-and-resources).

Instructions to add a new dataset can be found [here](https://github.com/huggingface/datasets/blob/master/ADD_NEW_DATASET.md).

cc @osanseviero