feat: update project configuration and structure

- Updated project.config.json with new project name and settings.
- Removed unused app.scss and index.scss files, replaced with CSS files.
- Refactored app.ts to utilize Taro's useLaunch hook for app initialization.
- Simplified index.tsx to display a basic greeting and user info button.
- Added new project.xhs.json for XHS platform configuration.
- Introduced is-xhs utility function to check for XHS environment.
- Updated tsconfig.json to include path mappings and additional include paths.

.eslintrc

@@ -1,4 +1,4 @@
-module.exports = {
+{
   "extends": ["taro/react"],
   "rules": {
     "react/jsx-uses-react": "off",