Remove links for all docs
Now that someone has done an awesome version selector for the docs, there's no need to list all versions in the README.
# [Codecov](https://codecov.io/gh/huggingface/transformers/pull/5280?src=pr&el=h1) Report
> Merging [#5280](https://codecov.io/gh/huggingface/transformers/pull/5280?src=pr&el=desc) into [master](https://codecov.io/gh/huggingface/transformers/commit/0e1fce3c0129d05b65a83cdd89e8eadded553f2e&el=desc) will **decrease** coverage by `0.02%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/huggingface/transformers/pull/5280/graphs/tree.svg?width=650&height=150&src=pr&token=9qOlN6Hb1c)](https://codecov.io/gh/huggingface/transformers/pull/5280?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master    #5280      +/-   ##
==========================================
- Coverage   79.11%   79.08%   -0.03%     
==========================================
  Files         138      138              
  Lines       24080    24080              
==========================================
- Hits        19050    19043       -7     
- Misses       5030     5037       +7     
```


| [Impacted Files](https://codecov.io/gh/huggingface/transformers/pull/5280?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [src/transformers/modeling\_openai.py](https://codecov.io/gh/huggingface/transformers/pull/5280/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ19vcGVuYWkucHk=) | `79.51% <0.00%> (-1.39%)` | :arrow_down: |
| [src/transformers/modeling\_tf\_pytorch\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/5280/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ190Zl9weXRvcmNoX3V0aWxzLnB5) | `88.05% <0.00%> (-1.26%)` | :arrow_down: |
| [src/transformers/modeling\_tf\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/5280/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ190Zl91dGlscy5weQ==) | `87.62% <0.00%> (-0.15%)` | :arrow_down: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/huggingface/transformers/pull/5280?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/5280?src=pr&el=footer). Last update [0e1fce3...49327ba](https://codecov.io/gh/huggingface/transformers/pull/5280?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
