NODE.JS + MONGODB CRUD

1. Install Node.js and MongoDB, or create a MongoDB Atlas database.
2. Open terminal in this folder.
3. Run: npm install
4. Start MongoDB locally, or set MONGO_URI to your Atlas connection string.
5. Run: npm start
6. Open http://localhost:3000

Endpoints:
GET    /students       list students
POST   /students       create student; JSON body e.g. {"name":"Arun","mark":85}
GET    /students/:id   read one student
PUT    /students/:id   update student; JSON body e.g. {"mark":90}
DELETE /students/:id   delete student

Use Postman, Thunder Client, or another API client for POST/PUT/DELETE requests.
