🌐 [i18n-KO] Translated package_reference/serialization.md to Korean

[seoyoung-3060]

What does this PR do?

Translated the package_reference/serialization.md file of the documentation to Korean.
Thank you in advance for your review.

Part of #1626

Before reviewing

• Check for missing / redundant translations (번역 누락/중복 검사)
• Grammar Check (맞춤법 검사)
• Review or Add new terms to glossary (용어 확인 및 추가)
• Check Inline TOC (e.g. [[lowercased-header]])
• Check live-preview for gotchas (live-preview로 정상작동 확인)

Who can review? (Initial)

Team Hugging Face KREW, may you please review this PR?
@harheem, @cjfghk5697, @seoulsky-field, @nuatmochoi, @boyunJang, @SeungAhSon, @seoyoung-3060, @junejae, @usr-bin-ksh, @fabxoe

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,
  Pull Request section?
• Was this discussed/approved via a Github issue or the forum? 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, and
  here are tips on formatting docstrings.
• Did you write any new necessary tests?

Who can review? (Final)

[cjfghk5697]

@seoyoung-3060
PR에 guides/search까지 같이 올라온거 같아요..! 혹시 몰라 말씀드립니다! 좋은 번역 감사합니다 ㅎㅎ