Add backend functionality

[Bhanu-code]

add backend functionality with firebase

[njangid22]

assign me this issue i want to add a basic backend server using Node.js and Express.js to handle form submissions from a contact form on a website. It also uses the Nodemailer library to send an email notification with the form data when a user submits the form. #hacktoberfest2023

[Bhanu-code]

no issues, take it @njangid22

[njangid22]

i added one feature in pull request #5 please merge that