text: Title: Documentation Notebooks
  Body: Hello, I was going through some documentation notebooks, and noticed that many of them ([Poincare Embeddings](https://github.com/RaRe-Technologies/gensim/blob/develop/docs/notebooks/Poincare%20Tutorial.ipynb), [WikiNews](https://github.com/RaRe-Technologies/gensim/blob/develop/docs/notebooks/wikinews-bigram-en.ipynb), [Varembed](https://github.com/RaRe-Technologies/gensim/blob/develop/docs/notebooks/Varembed.ipynb)) have been uploaded without being run to the end, they fail with errors halfway through.
  
  @piskvorky (and others), would it be useful to have these updated? Or is someone from the RaRe / gensim team in charge of documentation?