Fix: update Discord links and enhance community page #9

[Justxd22]

This PR addresses Issue #9 by fixing broken Discord links across the website, introducing a permanent invite link, and significantly enhancing the Community page with new resources.

Changes

• Global:
  • Created lib/constants.ts to manage social links (Discord, GitHub, Twitter, etc.) in one place.
  • Replaced all hardcoded/placeholder Discord links with the permanent invite: https://discord.gg/xjwZzGKDVR.
  • Linked CODE_OF_CONDUCT.md from main repo.
• Community Page (app/community/page.tsx):
  • Added a new GitHub Discussions section with category overviews.
  • Added a Community Guidelines section linking to the Code of Conduct.
  • Enhanced the "Connect With Us" section to serve as a visual banner for community channels.
  • Ensured all external links open in a new tab (target="_blank").
• Footer & Contact Page:
  • Updated to use the centralized SOCIAL_LINKS constants.
  • Fixed external link behavior to ensure they open in a new tab.

✅ Checklist

• Permanent Discord invite link implemented
• All Discord links updated across the site
• GitHub Discussions section added
• Community Guidelines section added
• External links open in new tab