Fix reference list descriptions to actually render italic

The description column in the reference list grid used font-italic,
which is not a Tailwind utility (the font-style utilities are italic
and not-italic), so the class was silently dropped and the text
rendered upright. Use the real utility.

Author: GuanzhouSong

app/components/Grid.tsx

@@ -16,7 +16,7 @@ export default function Grid({ items }: {
             <h4 className="text-blue-300 font-mono font-medium group-hover:text-blue-200">
               {page.name}
             </h4>
-            <p className="text-xs text-gray-400 font-italic">
+            <p className="text-xs text-gray-400 italic">
               {page.description}
             </p>
           </div>