Add .vs to gitignore
My VS code writes stuff there so added it to the .gitignore.

I also have other untracked files:
- in tests/fixtures/ I have some cached_lm_\*Tokenizer_\*.txt and .txt.lock after running the tests
- in docs/ I have the simlink to examples.md as indicated in [here](https://github.com/huggingface/transformers/tree/master/docs#building-the-documentation)

Should I add stuff in .gitignore to ignore those as well?
# [Codecov](https://codecov.io/gh/huggingface/transformers/pull/4774?src=pr&el=h1) Report
> Merging [#4774](https://codecov.io/gh/huggingface/transformers/pull/4774?src=pr&el=desc) into [master](https://codecov.io/gh/huggingface/transformers/commit/cd4e07a85e6161111016ca6d811d97e59368971a&el=desc) will **increase** coverage by `0.22%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/huggingface/transformers/pull/4774/graphs/tree.svg?width=650&height=150&src=pr&token=9qOlN6Hb1c)](https://codecov.io/gh/huggingface/transformers/pull/4774?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master    #4774      +/-   ##
==========================================
+ Coverage   77.09%   77.32%   +0.22%     
==========================================
  Files         128      128              
  Lines       21059    21059              
==========================================
+ Hits        16235    16283      +48     
+ Misses       4824     4776      -48     
```


| [Impacted Files](https://codecov.io/gh/huggingface/transformers/pull/4774?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [src/transformers/modeling\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/4774/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ191dGlscy5weQ==) | `90.15% <0.00%> (+0.12%)` | :arrow_up: |
| [src/transformers/modeling\_tf\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/4774/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ190Zl91dGlscy5weQ==) | `88.96% <0.00%> (+0.16%)` | :arrow_up: |
| [src/transformers/modeling\_gpt2.py](https://codecov.io/gh/huggingface/transformers/pull/4774/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ19ncHQyLnB5) | `86.39% <0.00%> (+14.55%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/huggingface/transformers/pull/4774?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/4774?src=pr&el=footer). Last update [cd4e07a...e51cd58](https://codecov.io/gh/huggingface/transformers/pull/4774?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
