docs(readme): update migration guide

ArrayZoneYour · ArrayZoneYour · commit c1531e754fb1 · 2021-08-04T20:37:31.000+08:00
diff --git a/README.md b/README.md
@@ -737,7 +737,7 @@ const Counter = createStore(() => {
       })
     }
   }
-  return [state, actions]
+  return [state, actions] as const
 })
 
 export default Counter

Original file line number	Diff line number	Diff line change
`@@ -737,7 +737,7 @@ const Counter = createStore(() => {`
`737`	`737`	`})`
`738`	`738`	`}`
`739`	`739`	`}`
`740`		`- return [state, actions]`
	`740`	`+ return [state, actions] as const`
`741`	`741`	`})`
`742`	`742`
`743`	`743`	`export default Counter`