Fix Korean Translation

[yoohaemin]

The Korean translation of the documentation seems to require a lot of fixing overall, from simple typos and grammatical mistakes to ambiguous and sometimes downright wrong wording.

• [ ] README.md
• [ ] SUMMARY.md
• [ ] getting-started.md
• [ ] application-structure.md
• [ ] the-client.md
• [ ] routing.md
• [ ] main-menu.md
• [ ] dashboard.md
• [ ] css-in-scala.md
• [ ] integrating-javascript-components.md
• [ ] todo-module-and-data-flow.md
• [ ] autowire-and-boopickle.md
• [ ] server-side.md
• [ ] testing.md
• [ ] debugging.md
• [ ] logging.md
• [ ] sbt-build-definition.md
• [ ] using-resources-from-webjars.md
• [ ] production-build.md
• [ ] faq.md
• [ ] what-next.md

[mcdoyaji]

+1