🌐 Add Korean translation for Tutorial - First Steps

[hard-coders]

This PR translates tutorial/first-steps.md in Korean.

related: #2017

[github-actions]

📝 Docs preview for commit 5669fc1 at: https://5fa7b1685ea3509d3d105d31--fastapi.netlify.app

[codecov]

Codecov Report

Merging #2323 (d576c32) into master (368d314) will increase coverage by 0.08%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           master     #2323      +/-   ##
===========================================
+ Coverage   99.91%   100.00%   +0.08%     
===========================================
  Files         243       243              
  Lines        7419      7419              
===========================================
+ Hits         7413      7419       +6     
+ Misses          6         0       -6     

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[github-actions]

📝 Docs preview for commit 229300a at: https://5fb8d326f652361a878832c6--fastapi.netlify.app

[PandaHun]

It's almost there!

[github-actions]

📝 Docs preview for commit bc63484 at: https://601f6f84b9896f0a7a4c3ccb--fastapi.netlify.app

[github-actions]

📝 Docs preview for commit b48f370 at: https://601f70e98baccaf21a32fccf--fastapi.netlify.app

[tiangolo]

Great! Thank you @hard-coders ! 🙇 🚀

And thanks for the reviews @PandaHun and @Suyoung789 ! 🍰