Update README.md

Tkc · web-flow · commit fbc35758adbe · 2020-03-11T08:29:38.000+09:00
diff --git a/README.md b/README.md
@@ -100,7 +100,7 @@ $ go-json-server
 ```
 
 `user.json`
-```
+```javascript
 {
   "id": 1,
   "name": "name",
