Update README.md

Author: ApolloZhu

README.md

@@ -5,6 +5,9 @@ An easy way to store anything anywhere -- UserDefaults, KeychainAccess, YYCache,
 ```swift
 @EFStorageUserDefaults(forKey: "username", defaultsTo: User.Name.random())
 var username: String
+
+// Or, if you don't like constraints,
+UserDefaults.efStorage.username = "OwO"
 ```
 
 See [Wiki](https://github.com/EFPrefix/EFStorage/wiki) for details on how to use `EFStorage`.