Fix createProxy call in README

Author: hectorj

README.md

@@ -92,7 +92,7 @@ export const store = new Vuex.Store({
 
 // Creating proxies.
 const vxm = {
-  user: createProxy( UserStore ),
+  user: createProxy( store, UserStore ),
 }
 ```
 
@@ -260,4 +260,4 @@ export class UserStore extends createModule({ target: "nuxt" }) {
 ```
 
 ## See Old API
-[Old API >](old-api-readme.md)
+[Old API >](old-api-readme.md)