🌟 New model addition

Model description

Hi, I would love to try contributing TFDPR . This is the first time to me, so I need some suggestions.
I have followed @sshleifer 's great PR on TFBart model on 4 files : __init__.py , convert_pytorch_checkpoint_to_tf2.py , utils/dummy_tf_objects.py and (newly created) modeling_tf_dpr.py

Now the TF model works properly and can load Pytorch's weights successfully the same output as Pytorch's counterparts except small random noise (1e-5) which I suspect of some dtypes different , but I could not find the cause.

I guess I need to add document on docs/source/model_doc/dpr.rst , and that's all ?
My question is do I need to change / fix any other files ? and/or do I need to do some other thing before making PR ?

To resolve TF vs. Pytorch naming issues, there's one change regarding TFBertModel vs. TFBertMainLayer as discussed here .
Thanks to @sshleifer for his help to solve the issue.

Open source status

• the model implementation is available: (give details)
  You can see all the modified codes with test run at :
  https://colab.research.google.com/drive/1lU4fx7zkr-Y3CXa3wmHIY8yJhKdiN3DI?usp=sharing
  (to easily navigate the changes, please “find on page” for e.g. TFDPRContextEncoder )

• the model weights are available: (give details)
  At the moment, I use existing Pytorch weights, but will upload TF weights too.

• who are the authors: (mention them, if possible by @gh-username)
  @ratthachat