docs: add JSON-LD schemas to docs (#14007)

www/apps/ui/app/globals.css

@@ -14,7 +14,7 @@
   }
 
   *::selection {
-    @apply bg-medusa-bg-highlight;
+    @apply bg-medusa-fg-subtle text-medusa-fg-on-inverted;
   }
 
   *:not(.code-block-elm) {

www/apps/ui/app/layout.tsx

@@ -15,8 +15,7 @@ export const metadata: Metadata = {
     template: `%s - ${config.titleSuffix}`,
     default: config.titleSuffix || "",
   },
-  description:
-    "Learn about Medusa UI, A React package with primitives for building Medusa applications.",
+  description: config.description,
   metadataBase: new URL(
     process.env.NEXT_PUBLIC_BASE_URL || "http://localhost:3000"
   ),