Update README.md

Author: ehmicky

README.md

@@ -217,12 +217,12 @@ Permission type as an object such as `{ user: { read: true, write: false } }`.
 
 The full syntax is:
 
-```js
+```json
 {
-  "user": { "read": "true", "write": "true", "execute": "true" },
-  "group": { "read": "true", "write": "true", "execute": "true" },
-  "others": { "read": "true", "write": "true", "execute": "true" },
-  "special": { "setuid": "true", "setgid": "true", "sticky": "true" }
+  "user": { "read": true, "write": true, "execute": true },
+  "group": { "read": true, "write": true, "execute": true },
+  "others": { "read": true, "write": true, "execute": true },
+  "special": { "setuid": true, "setgid": true, "sticky": true }
 }
 ```