feat: initialize Astro project with Tailwind and TypeScript

- Astro 5.0 with TypeScript strict mode
- Tailwind CSS 3.4 configured with custom design system
- Project structure created (components, layouts, content, styles)
- Sitemap and RSS integrations added
- Build verified successfully

Fixes dependency conflict by using Astro 5 instead of 6

tsconfig.json

@@ -0,0 +1,5 @@
+{
+  "extends": "astro/tsconfigs/strict",
+  "include": [".astro/types.d.ts", "**/*"],
+  "exclude": ["dist"]
+}