Example configurations

[dennybritz]

Writing configuration files with hyperparameters from scratch is difficult because there are lot of options. We should provide a few examples hyperparameter configurations for models. For example:

• Large NMT: Configuration for large NMT/Summarization models that can get state of the art results
• Medium NMT: Medium-size NMT model that does reasonable well and is faster to train than the large model
• Small NMT: NMT model that is very fast to train but probably doesn't do very well.

If we decide to add image captioning support we should also add configuration files for that.