[Community notebooks] Add notebook on fine-tuning GPT-2 Model with Trainer Class
Adding a link to a community notebook containing an example of fine-tuning a German GPT-2 Model with the Trainer Class
# [Codecov](https://codecov.io/gh/huggingface/transformers/pull/7005?src=pr&el=h1) Report
> Merging [#7005](https://codecov.io/gh/huggingface/transformers/pull/7005?src=pr&el=desc) into [master](https://codecov.io/gh/huggingface/transformers/commit/c18f5916a03d0a161d003e95ffff8120d8addc0c?el=desc) will **decrease** coverage by `0.59%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/huggingface/transformers/pull/7005/graphs/tree.svg?width=650&height=150&src=pr&token=9qOlN6Hb1c)](https://codecov.io/gh/huggingface/transformers/pull/7005?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master    #7005      +/-   ##
==========================================
- Coverage   80.63%   80.03%   -0.60%     
==========================================
  Files         161      161              
  Lines       30123    30123              
==========================================
- Hits        24289    24109     -180     
- Misses       5834     6014     +180     
```


| [Impacted Files](https://codecov.io/gh/huggingface/transformers/pull/7005?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [src/transformers/modeling\_tf\_electra.py](https://codecov.io/gh/huggingface/transformers/pull/7005/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ190Zl9lbGVjdHJhLnB5) | `25.13% <0.00%> (-73.83%)` | :arrow_down: |
| [src/transformers/data/data\_collator.py](https://codecov.io/gh/huggingface/transformers/pull/7005/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9kYXRhL2RhdGFfY29sbGF0b3IucHk=) | `91.90% <0.00%> (-0.81%)` | :arrow_down: |
| [src/transformers/modeling\_tf\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/7005/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ190Zl91dGlscy5weQ==) | `86.97% <0.00%> (-0.33%)` | :arrow_down: |
| [src/transformers/file\_utils.py](https://codecov.io/gh/huggingface/transformers/pull/7005/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9maWxlX3V0aWxzLnB5) | `82.66% <0.00%> (+0.25%)` | :arrow_up: |
| [src/transformers/modeling\_tf\_flaubert.py](https://codecov.io/gh/huggingface/transformers/pull/7005/diff?src=pr&el=tree#diff-c3JjL3RyYW5zZm9ybWVycy9tb2RlbGluZ190Zl9mbGF1YmVydC5weQ==) | `88.34% <0.00%> (+63.80%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/huggingface/transformers/pull/7005?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/7005?src=pr&el=footer). Last update [c18f591...0d1e538](https://codecov.io/gh/huggingface/transformers/pull/7005?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
