* Added "dotenv" dependency to package.json
Since the project is using .env file for fetching the port, it had no "dotenv" dependency. This creates confusion when "process.env.PORT" doesn't work. I hope this is convenient for beginners 👍
* Update server.js
Added a line to import `dotenv` dependency to server.js.
* Update package-lock.json
I have added the dotenv dependency to package-lock.json file as requested. I hope it's good now