MultiBerts in Huggingface
# 🚀 Feature request

It would be nice to have a script/converter of all the [multiberts](https://arxiv.org/pdf/2106.16163.pdf) checkpoints that were released about a month ago.
It was [released](https://github.com/google-research/language/tree/master/language/multiberts) by Google, thus using tensorflow, and it would be nice to have it under the huggingface library/hub.

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## Motivation

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These checkpoints may be useful to study training dynamics and hypotheses over multiple seeds that were used to train the model.
