feat: enhance landing page UI/UX

[Gracing47]

 Closes #34 in https://github.com/celo-org/composer-kit/issues/34

 This PR enhances the landing page UI with several improvements:

 ### Changes
 - Added a modern hero section with gradient background
 - Implemented feature grid showcasing key capabilities
 - Enhanced wallet connection status display with network indicator
 - Added Discord link to footer
 - Improved visual transitions and gradients

 ### Technical Details
 - Used Tailwind CSS for responsive design
 - Implemented Next.js best practices
 - Ensured mobile-friendly layout
 - Added proper hover states and animations

 ### Screenshot

 ### Testing
 - Tested on desktop and mobile viewports
 - Verified wallet connection status
 - Confirmed all links are working
 - Checked responsive behavior

[netlify]

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