Link pre-trained models from docs

[papajohn]

Would you please consider linking pre-trained models for each of the configurations in https://github.com/google/seq2seq/tree/master/example_configs from the docs?

Lots of exploratory research involves fine-tuning an existing model, looking at output, applying a model in a new way, etc. So, lots of people are really just training the same thing (for a week).

E.g., OpenNMT models are shared here: http://opennmt.net/Models/

[coventry]

Are there any third-party pretrained models out there? Training one up myself is proving expensive.

[matthias-samwald]

Additionally / alternatively, we from the user community could share trained models and results of different settings (at the moment I'm seeing what effect layer norm has on the big model...).

[PapaMadeleine2022]

@papajohn @coventry @matthias-samwald I also need the pre-trained models for English to German or other languages. Do you get the link?