fix: Add valid email checker while subscribing

[Ishika-Gupta06]

Title : valid Email while Subscribing

Issue No. : #1547

Code Stack : html, JavaScript

Close #1547

Description

improve the regex to ensure the domain part is properly validated (e.g., at least two characters after the dot). Added an email validation regex (email Pattern) to check the input format. If the email is valid, the success message is displayed. If the email is invalid, an error message is displayed for 4 seconds.

Video/Screenshots (mandatory)

https://github.com/user-attachments/assets/313757b3-5674-4068-b16a-e7f806f403f8

Type of PR

• [X] Bug fix
• [ ] Feature enhancement
• [ ] Documentation update
• [ ] Other (specify): ___

Checklist:

• [X] I have performed a self-review of my code.

• [X] I have commented my code, particularly in hard-to-understand areas.

• [X] I have tested the changes thoroughly before submitting this pull request.

• [X] I have provided relevant issue numbers, screenshots, and videos after making the changes.

• [X] I have gone through the contributing.md file before contributing

• [X] I have Starred the Repository.

• [X] I am contributing under GSSOC'24 Extended

• [X] I am contributing under Hacktoberfest'24

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[IRONalways17]

This pull request includes changes to the index.html file to improve the user experience and validation for the subscription form. The most important changes include adding an error message for invalid email addresses, improving the email validation regex, and refactoring the JavaScript code for better readability and functionality.

User Experience Improvements:

• Added an error message to notify users when they enter an invalid email address. (index.html index.htmlL1982-R1998)

Validation Enhancements:

• Improved the email validation regex to check for a valid domain. (index.html index.htmlL1982-R1998)

Code Refactoring:

• Refactored JavaScript code to handle form submission more effectively by showing appropriate messages based on email validity. (index.html [1] [2]

[Ishika-Gupta06]

@apu52 kindly review the PR

[github-actions[bot]]

🎉🎉 Thank you for your contribution! Your PR #1557 has been merged! 🎉🎉