feat: add content system with MDX support, types, and meta files for 4 games

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

content/ragnarok/meta.json

@@ -0,0 +1,8 @@
+{
+  "title": "Ragnarok Online",
+  "subtitle": "La Saga de Midgard",
+  "description": "En un mundo donde dioses y mortales coexisten, la tierra de Midgard se enfrenta a amenazas que podrian desatar el Ragnarok, el fin de todas las cosas.",
+  "color": "#8b2500",
+  "colorDark": "#5c1a00",
+  "accentColor": "#ff8c42"
+}