feat(storefront): update FAQ and legal documentation

- Added new FAQ sections for account security, ordering and checkout, returns, shipping, and contact information.
- Introduced legal documents including privacy policy, terms of service, data protection, and general terms and conditions.
- Updated package dependencies to include gray-matter and remark-gfm for enhanced markdown support.

apps/storefront/src/app/legal/general-terms-and-conditions/page.tsx

@@ -0,0 +1,15 @@
+import { LegalDocPage } from "@/components/legal/LegalDocPage";
+import { getLegalDoc } from "@/lib/legal/getLegalDoc";
+import type { Metadata } from "next";
+
+export async function generateMetadata(): Promise<Metadata> {
+  const doc = getLegalDoc("general-terms-and-conditions");
+  return {
+    title: doc?.data.title ?? "General Terms and Conditions",
+    description: doc?.data.description,
+  };
+}
+
+export default function GeneralTermsAndConditionsPage() {
+  return <LegalDocPage slug="general-terms-and-conditions" />;
+}