Revert "change README for Usage"

This reverts commit fa8dde1.

README.md

@@ -8,36 +8,8 @@
 
 ## Usage
 
-Use this package as a library
-1. Depend on it
-Add this to your package's pubspec.yaml file:
-
-```
-dependencies:
-  flutter_aes_ecb_pkcs5: ^0.1.1
-```
-
-2. Install it You can install packages from the command line:
-
-with Flutter:
-
-```
-$ flutter pub get
-```
-
-Alternatively, your editor might support flutter pub get. Check the docs for your editor to learn more.
-
-3. Import it Now in your Dart code, you can use:
-
-```
-import 'package:flutter_aes_ecb_pkcs5/flutter_aes_ecb_pkcs5.dart';
-```
-
-
-
-#### AES Use Example
-
 
+#### AES
 
 ```dart
 import 'package:flutter_aes_ecb_pkcs5/flutter_aes_ecb_pkcs5.dart';
@@ -46,15 +18,15 @@ void main() {
 
     var data = "{\"username\":\"helloword\"}";
     
-    //generate a 16-byte random key
+    //生成16字节的随机密钥
     var key = await FlutterAesEcbPkcs5.generateDesKey(128);
     
     print(key);
-    //encrypt
+    //加密
     var encryptText = await FlutterAesEcbPkcs5.encryptString(data, key);
     
     print(encryptText);
-    //decrypt
+    //解密
     var decryptText  = await FlutterAesEcbPkcs5.decryptString(encryptText, key);
     
     print(decryptText);