Add custom task (bac-fr) for evaluation of models in french (#518)
* Add custom task (bac-fr) for evaluation of models in french
* Update prompt function for the bac-fr task
Co-authored-by: Clémentine Fourrier <22726840+clefourrier@users.noreply.github.com>
* Add metrics for the evaluation of bac-fr
* Fix function name (as_list)
* Fix prompt for multichoice
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Co-authored-by: Clémentine Fourrier <22726840+clefourrier@users.noreply.github.com>