Add Doc Test for BERT (#16523)
* Add doctest BERT
* make fixup
* fix typo
* change checkpoints
* make fixup
* define doctest output value, update doctest for mobilebert
* solve fix-copies
* update QA target start index and end index
* change checkpoint for docs and reuse defined variable
* Update src/transformers/models/bert/modeling_tf_bert.py
Co-authored-by: Yih-Dar <2521628+ydshieh@users.noreply.github.com>
* Apply suggestions from code review
Co-authored-by: Yih-Dar <2521628+ydshieh@users.noreply.github.com>
* Apply suggestions from code review
Co-authored-by: Yih-Dar <2521628+ydshieh@users.noreply.github.com>
* make fixup
Co-authored-by: Yih-Dar <2521628+ydshieh@users.noreply.github.com>