feat: update branding assets and fix build errors (fixes #2)

[Dheemanth07]

Resolves #2

Changes Made

• Assets: Added official branding (Logo, Favicon, Social Card) to static/img/.
• Config: Updated docusaurus.config.ts to point to the new assets.
• Cleanup: Removed unused default Docusaurus images (Undraw files) to keep the repo clean.
• Fix: Updated HomepageFeatures to use the new logo, resolving build errors caused by missing files.

Verification

• Build passes locally (npm start).
• Favicon displays correctly in the browser tab.
• Social card preview uses the high-res brand icon.

[Dheemanth07]

Since the default undraw assets were deleted, I used the main project logo as a placeholder for the three feature sections to ensure the build passes without errors.
If you have specific icons you'd like to use for "Open Source," "Contributing," and "Community," please share them and I will update the code!