Update Cloudflare deployment guide and configuration for Samplestep frontend

Commit notes

- Revised the deployment guide to reflect the new project name and updated integration with React Router and Cloudflare. - Created `wrangler.jsonc` for Cloudflare Workers configuration, replacing the deprecated `wrangler.toml`. - Added `workers/app.ts` as the entry point for handling requests with Cloudflare. - Updated `react-router.config.ts` to enable compatibility with the Cloudflare Vite plugin. - Adjusted deployment scripts in `package.json` to ensure proper execution with PNPM. - Enhanced project structure documentation to clarify the organization of files and resources.