Add Safari internal JS services and documentation

js/schema/SchemaOrgMarkupChecker.js

@@ -0,0 +1,20 @@
+//# sourceURL=__InjectedScript_SchemaOrgMarkupChecker.js
+/* Copyright (c) 2025 Apple Inc. All rights reserved. */
+(function () {
+  const e = "schema.org";
+  var t = document.querySelectorAll('script[type="application/ld+json"]');
+  for (let o of t) {
+    var r;
+    try {
+      r = JSON.parse(o.text);
+    } catch (e) {
+      continue;
+    }
+    if (r["@context"].toLowerCase().includes(e)) return !0;
+  }
+  var o = document.querySelectorAll("[itemscope]");
+  for (let t of o) {
+    var c = t.getAttribute("itemType");
+    if (c && c.toLowerCase().includes(e)) return !0;
+  }
+})();