Update README.md
Fix missig "-" in meta data
# [Codecov](https://codecov.io/gh/huggingface/transformers/pull/5812?src=pr&el=h1) Report
> Merging [#5812](https://codecov.io/gh/huggingface/transformers/pull/5812?src=pr&el=desc) into [master](https://codecov.io/gh/huggingface/transformers/commit/89a78be51f1c2afd263da66ec76d3297432f0c2a&el=desc) will **increase** coverage by `0.31%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/huggingface/transformers/pull/5812/graphs/tree.svg?width=650&height=150&src=pr&token=9qOlN6Hb1c)](https://codecov.io/gh/huggingface/transformers/pull/5812?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master    #5812      +/-   ##
==========================================
+ Coverage   78.19%   78.50%   +0.31%     
==========================================
  Files         146      146              
  Lines       26047    26047              
==========================================
+ Hits        20367    20448      +81     
+ Misses       5680     5599      -81     
```


| [Impacted Files](https://codecov.io/gh/huggingface/transformers/pull/5812?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [src/transformers/modeling\_tf\_distilbert.py](https://codecov.io/gh/huggingface/transformers/pull/5812/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ190Zl9kaXN0aWxiZXJ0LnB5) | `64.90% <0.00%> (-33.90%)` | :arrow_down: |
| [src/transformers/generation\_tf\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/5812/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9nZW5lcmF0aW9uX3RmX3V0aWxzLnB5) | `86.21% <0.00%> (ø)` | |
| [src/transformers/modeling\_openai.py](https://codecov.io/gh/huggingface/transformers/pull/5812/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ19vcGVuYWkucHk=) | `82.31% <0.00%> (+1.28%)` | :arrow_up: |
| [src/transformers/modeling\_tf\_openai.py](https://codecov.io/gh/huggingface/transformers/pull/5812/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ190Zl9vcGVuYWkucHk=) | `95.18% <0.00%> (+74.91%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/huggingface/transformers/pull/5812?src=pr&el=continue).
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> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/huggingface/transformers/pull/5812?src=pr&el=footer). Last update [89a78be...a5f39ab](https://codecov.io/gh/huggingface/transformers/pull/5812?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
