Fix issue #112: Prevent download window from opening on incorrect input format

[Apo-orva17]

Description:
This PR addresses issue #112 where the download window was opening even when users entered details in an incorrect format. The fix adds proper validation to ensure the download window only opens if the input format is valid. Users will now receive feedback prompting them to correct their input before proceeding.

Changes Made:

• Implemented input format validation before triggering the download window.
• Added error messages to guide users when input is invalid.
• Updated UI behavior to block download window on invalid input.

Impact:

• Improves user experience by preventing unintended downloads.
• Reduces potential errors caused by invalid input formats.

Video Link:
https://drive.google.com/file/d/168OyoZnAdHQizqik_IcPf3OFF47oESRw/view?usp=sharing

Related Issue:
Closes #112

[netlify]

✅ Deploy Preview for resume-generator011 ready!

Name	Link
🔨 Latest commit	9f17130
🔍 Latest deploy log	https://app.netlify.com/projects/resume-generator011/deploys/68c5a252ef4572000851e39e
😎 Deploy Preview	https://deploy-preview-114--resume-generator011.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.

[Apo-orva17]

@rajdeep13-coder plz review this pr and approve it