[UI/UX] Update the “What is HackNC” container with the asset in Figma

[vihaan-kk]

Description

• Replace the “What is HackNC” container with the container asset in Figma: https://www.figma.com/design/W1mgcz5bSEXb9BdrbKnNMY/hacknc-2026-website?node-id=343-179&p=f&t=rmKQDHDylFEBPG3F-0
• Need to export the asset from Figma and overlay the current text over it
• Remove code for the current section/box layout and styling

Acceptance Criteria

• "What is HackNC" container exactly matches with Figma
• Text is overlayed correctly
• Frontend build, lint, and formatting checks pass.