feat: add CodeMirror-based code editor component and routing setup

- Implemented CodeEditor component using CodeMirror for JavaScript editing.
- Added global styles in index.css for consistent UI.
- Set up routing with TanStack Router, including root and nested routes.
- Created About, C, and Editor routes with respective components.
- Integrated CodeEditor into the Editor route for code editing functionality.
- Configured TypeScript settings in tsconfig.json for strict type checking.
- Established Vite configuration for React and TanStack Router integration.

package.json

@@ -0,0 +1,26 @@
+{
+  "name": "tanstack-router-app",
+  "version": "1.0.0",
+  "type": "module",
+  "scripts": {
+    "dev": "vite",
+    "build": "tsc && vite build",
+    "preview": "vite preview"
+  },
+  "dependencies": {
+    "@codemirror/lang-javascript": "^6.2.4",
+    "@tanstack/react-router": "^1.157.16",
+    "@uiw/react-codemirror": "^4.25.4",
+    "react": "^19.2.4",
+    "react-dom": "^19.2.4"
+  },
+  "devDependencies": {
+    "@tanstack/react-router-devtools": "^1.157.16",
+    "@tanstack/router-plugin": "^1.157.16",
+    "@types/react": "^19.2.10",
+    "@types/react-dom": "^19.2.3",
+    "@vitejs/plugin-react": "^5.1.2",
+    "typescript": "^5.9.3",
+    "vite": "^7.3.1"
+  }
+}