Tune ADR decoder parameters

[ruohoruotsi]

Fine-tune the seq2seq decoder parameters (like beam-width) for the ADR task. This also includes error-analysis from the validation & test sets so we have a deep understanding of the performance of the model.

Please refer to this document from the CMU-LTI: https://github.com/neubig/nmt-tips

[dadelani]

thanks for the sharing the CMU-LTI tips

[ruohoruotsi]

@toonday this is an example issue, you can find it on the project under next TODOs. Just a followup on the kind of small scale "project mgt" we're currently doing.