[i18n-KO] Translated `keypoint_detection.md` to Korean
Author: rlaalsrl0922
Pull request: yes

# What does this PR do?

Translated the `keypoint_detection.md` file of the documentation to Korean.
Thank you in advance for your review.

Part of https://github.com/huggingface/transformers/issues/20179

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Fixes # (issue)

## Before reviewing
- [x] Check for missing / redundant translations (번역 누락/중복 검사)
- [x] Grammar Check (맞춤법 검사)
- [x] Review or Add new terms to glossary (용어 확인 및 추가)
- [x] Check Inline TOC (e.g. `[[lowercased-header]]`)
- [x] Check live-preview for gotchas (live-preview로 정상작동 확인)


## Who can review? (Initial)

May you please review this PR?
@cjfghk5697, @yijun-lee, @MinJu-Ha

## Before submitting
- [ ] This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
- [ ] Did you read the [contributor guideline](https://github.com/huggingface/transformers/blob/main/CONTRIBUTING.md#create-a-pull-request),
      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.
- [ ] 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? (Final)
@stevhliu May you please review this PR?



Comments:
Hi 👋, thank you for opening this pull request! The pull request is converted to draft by default. When it is ready for review, please click the `Ready for review` button (at the bottom of the PR page).

Hi 👋, thank you for opening this pull request! The pull request is converted to draft by default. When it is ready for review, please click the `Ready for review` button (at the bottom of the PR page).

cc @stevhliu 

The docs for this PR live [here](https://moon-ci-docs.huggingface.co/docs/transformers/pr_36649). All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.

> Thanks for your translation!
> 
> cc @jungnerd, would you mind reviewing please if you have a chance? 🤗

Sure! I'll review it as soon as possible tomorrow 👍🏻

Thanks @jungnerd !

@rlaalsrl0922, can you please push an empty commit to trigger the `run_tests` check? Thanks again! 🤗