docs: document missing events in reference (#10779)

www/apps/resources/sidebars/payment.mjs

@@ -157,6 +157,11 @@ export const paymentSidebar = [
         description:
           "Find references for data models, methods, and more. These are useful for your customizations.",
         children: [
+          {
+            type: "link",
+            path: "/commerce-modules/payment/events",
+            title: "Events Reference",
+          },
           {
             type: "link",
             path: "/references/payment",