public ActionResult UpdateSave(PhoneContact phoneContact)
        {
            _phoneContacts = _phoneContacts.Select(c => c.Id == phoneContact.Id ? new PhoneContact(phoneContact.Id, phoneContact.Name, phoneContact.Phone) : c).ToList();
            _phoneContacts = ContactsHandler.WriteToJsonFile(_phoneContacts);

            return(RedirectToAction("Index"));
        }
        public ActionResult DeleteSave(PhoneContact phoneContact)
        {
            _phoneContacts.RemoveAll(c => c.Id == phoneContact.Id);
            _phoneContacts = ContactsHandler.WriteToJsonFile(_phoneContacts);

            return(RedirectToAction("Index"));
        }
        public ActionResult AddSave(PhoneContact phoneContact)
        {
            _phoneContacts.Add(phoneContact);
            _phoneContacts = ContactsHandler.WriteToJsonFile(_phoneContacts);

            return(RedirectToAction("Index"));
        }