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.

convex/_generated/api.d.ts

@@ -17,6 +17,7 @@ import type * as checkoutActions from "../checkoutActions.js";
 import type * as emails from "../emails.js";
 import type * as fulfillmentActions from "../fulfillmentActions.js";
 import type * as http from "../http.js";
+import type * as messages from "../messages.js";
 import type * as model_carts from "../model/carts.js";
 import type * as model_categories from "../model/categories.js";
 import type * as model_checkout from "../model/checkout.js";
@@ -50,6 +51,7 @@ declare const fullApi: ApiFromModules<{
   emails: typeof emails;
   fulfillmentActions: typeof fulfillmentActions;
   http: typeof http;
+  messages: typeof messages;
   "model/carts": typeof model_carts;
   "model/categories": typeof model_categories;
   "model/checkout": typeof model_checkout;