feat/8-create-employee-modal

[ZcriptAlchemist]

Create User Modal

• [x] turn CreateUser.jsx component into a modal named CreateEmployeeModal.jsx.
  • [x] on click of a button, CreateEmployeeModal.jsx should pop up.
  • [x] create toast messages instead of alerts using react toastify package.
  • [x] use our application's design scheme, collar palletes, and aesthetics while creating user interface.