simple contact manager application

This project is a simple contact manager application that lets you create, view, edit, and delete contacts. It uses json-server as a mock REST API to store the contacts as JSON objects in a file called db.json. The application has a user interface that displays a list of contacts with their name, phone number, and email address. You can add a new contact by clicking on the Add Contact button and filling out a form with the required fields. You can also edit an existing contact by clicking on the Edit Contact button and modifying the fields as needed. You can delete a contact by clicking on the Delete Contact button and confirming your action. The application uses some functions to communicate with the json-server using HTTP methods such as GET, POST, PUT, and DELETE. The functions use fetch API to send requests and receive responses from the server. The application also handles errors and validations for the input fields.