[YeongGyu1110]

Summary

Adds the Korean translation of /docs/quick-start at /ko/docs/quick-start.

Closes #877

Changes

• Add apps/landing/src/app/(detail)/docs/quick-start/page.ko.mdx
  • Set the canonical URL to /ko/docs/quick-start and add English and Korean alternates
• Register /docs/quick-start in apps/landing/src/i18n/pages.ts, following the /docs/overview entry and reusing DocsLayout

Translation notes

• Terminology follows the Korean Overview page (for example, 스타일 속성 and 의사 선택자).
• Only explanatory code comments are translated. Code and strings inside code (such as Hover me) are unchanged.
• Internal links stay root-relative.
• The English page has no metadata description, so only the title is translated, as in the Korean Overview.
• The English page and other pages are unchanged.

Verification

Tested on Windows 11.

• bun install and bun run build from the repository root
• bun run build and node script.js from apps/landing
• Type check (tsc --noEmit -p apps/landing/tsconfig.json)
• bunx playwright test e2e/landing-i18n.spec.ts (6 passed; these tests do not target this page directly)
• In the built site, /ko/docs/quick-start renders the translation without redirecting, with correct canonical and hreflang tags
• /docs/quick-start still renders in English
• Code blocks and horizontal overflow checked on desktop and mobile (375px)
• All 5 "next steps" links checked (untranslated targets redirect to English)
• Korean search data includes 빠른 시작

Notes for reviewers

• bun dev could not be verified. In my Windows environment, every page returns a 500 because MDX reaches vite:oxc untransformed and fails with a PARSE_ERROR. The same error occurs on main without this change, so it is unrelated to this PR. I have not checked whether it reproduces on other platforms.
• Tests were run separately using the same commands as the pre-commit hook. bun lint, cargo tarpaulin and bun run test:bun all passed with no failures. cargo tarpaulin needed CARGO_BUILD_JOBS=2 because of memory limits and reported 98.22% line coverage locally. This PR has no Rust changes. The commit was made with --no-verify.
• Shared navigation, such as the sidebar, stays in English because it belongs to a separate issue.