docs: add link to manage metadata section in OAS and API reference (#13102)

www/utils/packages/docs-generator/src/classes/helpers/schema-factory.ts

@@ -109,6 +109,15 @@ class SchemaFactory {
         url: "#pagination",
       },
     },
+    metadata: {
+      type: "object",
+      title: "metadata",
+      description: "Holds custom key-value pairs.",
+      externalDocs: {
+        url: "https://docs.medusajs.com/api/store#manage-metadata",
+        description: "Learn how to manage metadata",
+      },
+    },
   }
 
   /**