Add AgentFinVQA project website

[aravind-3105]

Summary

Adds a public project landing page for AgentFinVQA on GitHub Pages: paper-style homepage with teaser figure, abstract, method, results, and quick-start sections. Replaces the generic MkDocs template docs with a single static site served from docs/index.html.

Clickup Ticket(s): N/A

Type of Change

• 🐛 Bug fix (non-breaking change that fixes an issue)
• ✨ New feature (non-breaking change that adds functionality)
• 💥 Breaking change (fix or feature that would cause existing functionality to not work as expected)
• 📝 Documentation update
• 🔧 Refactoring (no functional changes)
• ⚡ Performance improvement
• 🧪 Test improvements
• 🔒 Security fix

Changes Made

• Added docs/index.html — single-column project homepage (title/authors → teaser → intro, abstract, method, dataset, results, quick start, BibTeX)
• Added docs/style.css and docs/main.js (nav toggle, code copy, BibTeX copy)
• Added assets: Vector/AIXPERT logos, Teaser.jpeg, Teaser_color.jpeg
• Removed template pages: docs/user_guide.md, docs/api.md, docs/index.md
• Simplified mkdocs.yml — landing page only (removed nav, mkdocstrings plugin, unused markdown extensions)
• Updated .github/workflows/docs.yml to trigger docs builds on .jpeg/.jpg changes

Testing

• Tests pass locally (uv run pytest tests/)
• Type checking passes (uv run mypy <src_dir>)
• Linting passes (uv run ruff check src_dir/)
• Manual testing performed (describe below)

Manual testing details:

• Ran uv run mkdocs build — site builds successfully; docs/index.html and assets copied to site/
• Verified homepage layout: single-column hero, teaser image + caption, white background (no blue hero panel)
• Confirmed removed template docs no longer appear in MkDocs output

Screenshots/Recordings

Homepage includes FinMME qualitative teaser (docs/assets/Teaser.jpeg) with zero-shot vs agent comparison figure.

Related Issues

N/A

Deployment Notes

• Merging to main triggers the docs workflow and deploys to GitHub Pages (gh-pages)
• Live URL: https://vectorinstitute.github.io/AgentFinVQA/
• No migration steps; docs-only change, no runtime/config impact

Checklist

• Code follows the project's style guidelines
• Self-review of code completed
• Documentation updated (if applicable)
• No sensitive information (API keys, credentials) exposed