feat: add website components and pages for LexAI

- Implemented SiteHeader and SiteFooter components for consistent navigation and footer across the website.
- Created CommunityPage and ContributePage to provide information on community involvement and contribution guidelines.
- Developed DocsPage to serve as the main documentation hub, detailing features and installation instructions.
- Added HomePage to introduce LexAI and its functionalities, highlighting key features and privacy aspects.
- Established links.ts for centralized management of external links used throughout the website.
- Configured main.tsx for application entry point with React Router for navigation.
- Introduced styles.css for consistent styling across the website.
- Set up TypeScript configuration files for improved type checking and development experience.
- Configured Vite for building and serving the website.

docs/DESIGN_SYSTEM.md

@@ -0,0 +1,33 @@
+# Design system (LexAI website)
+
+## Principles
+
+- Quiet, professional, minimal. Typography and space do the work.
+- Fewest clicks to install or docs.
+- Privacy (BYO-key, no LexAI servers) is a first-class message.
+
+## Foundations
+
+| Token | Value |
+| --- | --- |
+| `--bg` | `#f7f7f5` |
+| `--surface` | `#ffffff` |
+| `--ink` | `#171717` |
+| `--muted` | `#5c5c57` |
+| `--line` | `#e6e6e2` |
+| `--indigo` | `#4f46e5` (logo tile) |
+| `--bolt` | `#f5c14a` (logo bolt) |
+| Mark | Flat rounded square + bolt (`LogoMark`) |
+| Type | Inter |
+
+Tap targets ≥ 40px; body text contrast AA.
+
+## Components
+
+| Component | Use |
+| --- | --- |
+| SiteHeader | Wordmark + Docs / Contribute / Community / Star on Gitea |
+| Hero | One kicker, one H1, one line, CTAs |
+| Feature list | Two-column hairline rows |
+| PackageCard | Chrome / VS Code / CLI |
+| DocsSection | Package docs blocks |