docs: ko: update `_toctree.yml`
# What does this PR do?

Part of https://github.com/huggingface/transformers/issues/20179
Initial version is in https://github.com/huggingface/transformers/pull/22581
Updated `_toctree.yml` according to https://github.com/huggingface/transformers/pull/23049

This PR restructures TOC for the documentation.
Here's the scope of the restructure:
a) TOC is sorted from “beginner” topics to more advanced
b) Some topics have been renamed
c) Task Guides are collapsed by default and now are on on the same level (currently NLP task guides are hidden, and not aligned with other modalities)
d) “General usage” has been renamed to “Developer Guides”
e) Benchmarks, notebooks, and community resources have been moved under Developer Guides
f) “Converting from TensorFlow checkpoints” and "Migrating from previous packages" pages removed

To dos:
Some topics have been renamed to be concise and more descriptive. Needs to translate to Korean.

## Before submitting
- [x] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
- [x] Did you read the [contributor guideline](https://github.com/huggingface/transformers/blob/main/CONTRIBUTING.md#start-contributing-pull-requests),
      Pull Request section?
- [ ] Was this discussed/approved via a Github issue or the [forum](https://discuss.huggingface.co/)? Please add a link
      to it if that's the case.
- [x] Did you make sure to update the documentation with your changes? Here are the
      [documentation guidelines](https://github.com/huggingface/transformers/tree/main/docs), and
      [here are tips on formatting docstrings](https://github.com/huggingface/transformers/tree/main/docs#writing-source-documentation).
- [ ] Did you write any new necessary tests?


## Who can review? (Initial)
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Team PseudoLab, may you please review this PR? @0525hhgus, @KIHOON71, @sim-so, @gabrielwithappy, @HanNayeoniee, @wonhyeongseo, @jungnerd

## Who can review? (Final)
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@sgugger, @ArthurZucker, @eunseojo May you please review this PR?
`ko/notebook.mdx`가 https://github.com/huggingface/transformers/pull/22670 에서 추가됐기 때문에 오류가 납니다. 삭제해주시면 안 날거예요<|||||>> `ko/notebook.mdx`가 #22670 에서 추가됐기 때문에 오류가 납니다. 삭제해주시면 안 날거예요. 제 닫은 브랜치를 다시 열어서 테스트 후 다시 나연님께 pr 보낼게요. merge하지 않고도 cherry-pick하는 방법이 있습니다. 이러면 squash할 때 더 간편한데, 그건 나중에 해보죠.

`notebook`이 문제가 된다는 부분까지는 파악하고 헤매고 있었네요.. 감사합니다!!
목차 수정하는게 쉽지 않네요 😂
내일 제 브랜치에 빌드 오류 없는지 확인해보겠습니다~<|||||>_The documentation is not available anymore as the PR was closed or merged._<|||||>> @MKhalusova Could you double-check this matches your latest changes?
> Thanks.

From what I can see it does match the changes, the structure is the same as in my changes. I can't verify the translation of the titles that were renamed, but it seems to be matching too. <|||||>> > @MKhalusova Could you double-check this matches your latest changes?
> > Thanks.
> 
> From what I can see it does match the changes, the structure is the same as in my changes. I can't verify the translation of the titles that were renamed, but it seems to be matching too.

Sorry that my reply is a little bit late. Not all renamed titles are translated in here.
Some titles have been renamed, but some are not (e.g. “General usage” has been renamed to “Developer Guides”)
Since changing title affects every document, [Pseudo Lab team](https://github.com/Pseudo-Lab) and I are going to translate all the renamed titles as we keep translating docs to Korean!