README.md

Setup transformers following instructions in README.md, (I would fork first).
```bash
git clone git@github.com:huggingface/transformers.git
cd transformers
pip install -e .
pip install pandas
```

Get required metadata
```
curl https://cdn-datasets.huggingface.co/language_codes/language-codes-3b2.csv  > language-codes-3b2.csv
curl https://cdn-datasets.huggingface.co/language_codes/iso-639-3.csv > iso-639-3.csv
```

Install Tatoeba-Challenge repo inside transformers
```bash
git clone git@github.com:Helsinki-NLP/Tatoeba-Challenge.git
```

To convert a few models, call the conversion script from command line:
```bash
python src/transformers/convert_marian_tatoeba_to_pytorch.py --models heb-eng eng-heb --save_dir converted
```

To convert lots of models you can pass your list of Tatoeba model names to `resolver.convert_models` in a python client or script.

```python
from transformers.convert_marian_tatoeba_to_pytorch import TatoebaConverter
resolver = TatoebaConverter(save_dir='converted')
resolver.convert_models(['heb-eng', 'eng-heb'])
```


### Upload converted models
```bash
cd converted
transformers-cli login
for FILE in *; do transformers-cli upload $FILE; done
```


### Modifications
- To change naming logic, change the code near `os.rename`. The model card creation code may also need to change.
- To change model card content, you must modify `TatoebaCodeResolver.write_model_card`