## What
- Migration create-react-app -> Vite-based SPA
- Not changed main UI & Logic, just did some refactoring:
  - Integrate Linter & Formatter
  - Applied Lint & Format for all files 🙏🏻
- Codebase organization ( migrated data fetching related logic to
`src/api/index.ts`)
- Minor changed trainign materials
- Confirmed to work with `node@20.18.2`, `node@21.7.3`, and
`node@22.13.1`
## Why
- De facto deprecation of create-react-app 😢
  - react/create-react-app#13072
  - reactjs/react.dev#5487
- When creating production-level applications, [it is recommended to use
frameworks like
**Next.js/Remix/GatsyBy/Astro**](https://react.dev/learn/start-a-new-react-project).
- However, these frameworks involve too many considerations beyond UI
implementation, such as hosting methods and rendering techniques
(CSR/SSR/SSG), making them unsuitable for educational purposes in build
education.
→ In Build training course, we decided to use **Vite-based Simple SPA**
## CHECKS  ⚠️
Please make sure you are aware of the following.
- [ ] **The changes in this PR doesn't have private information