GitLab

* Create modeling_flax_eletra with code copied from modeling_flax_bert

* Add ElectraForMaskedLM and ElectraForPretraining

* Add modeling test for Flax electra and fix naming and arg in Flax Electra model

* Add documentation

* Fix code style

* Create modeling_flax_eletra with code copied from modeling_flax_bert

* Add ElectraForMaskedLM and ElectraForPretraining

* Add modeling test for Flax electra and fix naming and arg in Flax Electra model

* Add documentation

* Fix code style

* Fix code quality

* Adjust tol in assert_almost_equal due to very small difference between model output, ranging 0.0010 - 0.0016

* Remove redundant ElectraPooler

* save intermediate

* adapt

* correct bert flax design

* adapt roberta as well

* finish roberta flax

* finish

* apply suggestions

* apply suggestions
Co-authored-by: Chris Nguyen <anhtu2687@gmail.com>