fix: update navbar as per latest website

[mohitkh7]

• Please check if the PR fulfills these requirements

• Screenshots for changes (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

• What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

  • Update Navbar as per latest website.

• What is the current behavior? (You can also link to an open issue here)

  • Existing navbar displays items as About, CFP, Venue etc.

• What is the new behavior (if this is a feature change)?

  • New Navbar displays items as Attend, Program, Sponsors etc.

• Other information:
  • Screenshot attached