Addition of MuRIL - BERT based model for 17 Indian Languages to the library
Hi,

This PR is regarding the addition of MuRIL, a BERT-based model trained specifically for 17 Indian Languages to the hugging face library.

MuRIL is released on tfhub. Link to the repo: [https://tfhub.dev/google/MuRIL/1](https://tfhub.dev/google/MuRIL/1)

I am interested to work on this contribution to the library. Please let me know if I can work on it.
Hello! Yes, feel free to. However, you seem to have based yourself off of a `tf` branch that is very old?<|||||>@LysandreJik Yeah sorry. Should I raise a new issue so that it can be changed accordingly?<|||||>If you want to contribute this model, I invite you to base yourself off of the `master` branch and create a new branch from there. 

Once you your branch, you can leverage the [template scripts](https://github.com/huggingface/transformers/tree/master/templates/adding_a_new_model) which should help you by creating a new model and adding it everywhere it should be added; you'll only have to update the created files.<|||||>Reading the [contributing guide](https://github.com/huggingface/transformers/blob/master/CONTRIBUTING.md) will also be very helpful.<|||||>great effort and contribution @ravi03071991 <|||||>@LysandreJik Sure. Will follow the guidelines. Thank you.