Create camembert-base-README.md
First version of our model_card for the original uploaded CamemBERT. 
@louismartin @pjox
# [Codecov](https://codecov.io/gh/huggingface/transformers/pull/3263?src=pr&el=h1) Report
> Merging [#3263](https://codecov.io/gh/huggingface/transformers/pull/3263?src=pr&el=desc) into [master](https://codecov.io/gh/huggingface/transformers/commit/afea70c01c7d2a844662a4d66b9f9d933cc6449c?src=pr&el=desc) will **increase** coverage by `0.11%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/huggingface/transformers/pull/3263/graphs/tree.svg?width=650&token=9qOlN6Hb1c&height=150&src=pr)](https://codecov.io/gh/huggingface/transformers/pull/3263?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master    #3263      +/-   ##
==========================================
+ Coverage   77.82%   77.93%   +0.11%     
==========================================
  Files          98       98              
  Lines       16666    16666              
==========================================
+ Hits        12970    12989      +19     
+ Misses       3696     3677      -19
```


| [Impacted Files](https://codecov.io/gh/huggingface/transformers/pull/3263?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [src/transformers/modeling\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/3263/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ191dGlscy5weQ==) | `93.84% <0%> (+0.13%)` | :arrow_up: |
| [src/transformers/modeling\_tf\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/3263/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ190Zl91dGlscy5weQ==) | `85.68% <0%> (+3.22%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/huggingface/transformers/pull/3263?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/huggingface/transformers/pull/3263?src=pr&el=footer). Last update [afea70c...14537eb](https://codecov.io/gh/huggingface/transformers/pull/3263?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
<|||||>Merged it (not sure it was ready yet, but feel free to update in another PR).

**[Model page](https://huggingface.co/camembert-base)**

Let us know if we can help in any way @benjamin-mlr @louismartin @pjox

You can also add 
```
---
language: french
---
```

on top of the README for the model to pop up when looking for FR models