Augtxt

* Word order errors added
* rename augtxt.augmenters.{wordaug,sentaug} to {wordtypo,senttypo}
* Sentence augmentation pipeline for word typos, interpuncation errors, and word order errors

* fasttext removed

* Deprecation warning that fasttext will be removed

* Sentence augementations
* Demo notebooks added
* interpunction augmentations

* German keyboard layout added

* Minor fixes