Add responsive research blog cards and local articles

[koo-ec]

Changes

• Design the Research & Insights page as illustrated cards, with four columns on wide screens, two on tablets, and one on phones.
• Add eight original article pages under docs/research/reddit/blogs/ with local card links and original SVG artwork.
• Credit and link the original University of Hull research group posts in four newly written summaries.
• Add all article pages to the documentation's text index and keep the main navigation concise.

Verification

• Parsed all eight SVG assets.
• Checked eight card links, image paths, article backlinks, in-article local links, and YAML navigation.
• Documentation CI will verify the generated site.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.

📢 Thoughts on this report? Let us know!