Initial setup: Korean community aggregator web app

- Set up Vite + React + TypeScript project
- Configure Tailwind CSS v4 with PostCSS
- Create project structure (components, types, data)
- Implement core features:
  - Header with search functionality
  - PostCard component for displaying posts
  - PostList with community filtering (전체/디씨/루리웹/아카)
  - PostModal for detailed post view
- Add mock data for 3 communities (DCInside, Ruliweb, Arcalive)
- Update README with project documentation

postcss.config.js

@@ -0,0 +1,6 @@
+export default {
+  plugins: {
+    '@tailwindcss/postcss': {},
+    autoprefixer: {},
+  },
+}