Make navbar sticky and improve footer design

[Gunjan10-droid]

Related Issue

Description

This PR makes the navbar sticky so it remains visible while scrolling, improving navigation usability.
It also enhances the footer design by:

• Adding better alignment and spacing
• Adding the logo
• Improving color scheme for a polished look
• Keeping social links + important navigation

Fixes #191

Type of PR

• Feature enhancement

Screenshots / videos (if applicable)

Checklist:

• I have made this change from my own.
• I have mentioned the issue number in my Pull Request.
• I have gone through the CONTRIBUTING.md file before contributing
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• My changes generate no new warnings.
• I have tested the changes thoroughly before submitting this pull request.
• I have provided relevant issue numbers and screenshots after making the changes.

[github-actions]

Thank you for submitting your pull request! 🙌 We'll review it as soon as possible.). If there are any specific instructions or feedback regarding your PR, we'll provide them here. Thanks again for your contribution! 😊

[vercel]

@Gunjan10-droid is attempting to deploy a commit to the Souvik's projects Team on Vercel.

A member of the Team first needs to authorize it.

[netlify]

❌ Deploy Preview for learnhub5 failed.

Name	Link
🔨 Latest commit	bca18d1
🔍 Latest deploy log	https://app.netlify.com/projects/learnhub5/deploys/68a87a18781e700008235b6a

[Gunjan10-droid]

@souvikpramanikgit can you reveiw the issue and merge it?

[github-actions]

🎉🎉 Thank you for your contribution! Your PR #224 has been merged! 🎉🎉