Added success message to the newsletter form

[akshay0611]

This PR enhances the newsletter subscription form by adding a success message that appears upon submission and disappears after 4 seconds. The input field resets after submission, improving user experience.

Changes:

• Added a success message that confirms subscription.
• Implemented JavaScript to hide the message after 4 seconds.
• Ensured the input field resets upon submission.

Fixes: #2

[Imran-imtiaz48]

Your JavaScript implementation for filtering and newsletter subscription is well-structured and efficient. The filterBox.setAttribute method dynamically updates the filter attribute, ensuring smooth interactivity. The event listener for the newsletter form prevents default submission, displays a success message, resets the form, and automatically hides the message after four seconds, enhancing user experience. Your code follows best practices, keeping it clean and easy to maintain. For improvement, consider adding animations to the success message for a smoother UX. Overall, this is a solid and functional implementation worth showcasing on GitHub...