feat: Implement website structure

- Add navigation with Themes, Puzzles, and Miscellany.
- Create "coming soon" pages for Puzzles and Miscellany.
- Create a Themes page with cards for various topics.
- Implement basic boxy layout.
- Prepare for future interactive additions and filtering.
- Set up for Netlify deployment.

src/pages/theme-pages/SocialChoice.tsx

@@ -0,0 +1,12 @@
+import ComingSoon from "@/components/ComingSoon";
+
+const SocialChoice = () => {
+  return (
+    <ComingSoon 
+      title="Social Choice Theory"
+      description="Understand voting systems, fairness criteria, and collective decision-making through interactive simulations. Explore Arrow's theorem, voting paradoxes, and electoral systems."
+    />
+  );
+};
+
+export default SocialChoice;