fix and cleanup like-terms notebook
fix and cleanup like-terms notebook

 - update to use more specific Int/Float types
 - update model to work with more strict data-validation
 - define specific model types and use them throughout the example

explosion/thinc,spacy-io/thinc,explosion/thinc,explosion/thinc,explosion/thinc,spacy-io/thinc,spacy-io/thinc