New recommendation models

[andrewtavis]

Please use this issue to make suggestions for new models that could be added to wikirec. Suggestions would ideally include some of the following:

• A blogpost or other source where the method is applied for related NLP tasks
• A research paper that details the method and its potential applications
• Source code for the method in Python or another language

Estimates of the model's efficacy would also be appreciated so that a new good first issue can be made and prioritized.

Thanks for any suggestions!

[andrewtavis]

#36 has been created for adding an embeddings neural network to wikirec.