fix readme

Author: lisong

README.md

@@ -92,7 +92,7 @@ $ vim config/config.js
 read [config.js](https://github.com/lisong/code-push-server/blob/master/config/config.js)
 
 
-## Storage mode [local/qiniu]
+## Storage mode [local/qiniu/s3]
 
 - 配置local存储,修改config/config.js中storageType值为local,配置中local下面storageDir和downloadUrl，如果不在同一台机器上，downloadUrl请指定域名或者ip地址
 

config/config.js

@@ -50,7 +50,7 @@ config.development = {
     // options value is (true | false), when it's true, it will cache updateCheck results in redis.
     updateCheckCache: false
   },
-  //config for smtp email，register module need validate user email project source https://github.com/nodemailer/nodemailer
+  // Config for smtp email，register module need validate user email project source https://github.com/nodemailer/nodemailer
   smtpConfig:{
     host: "smtp.mxhichina.com",
     port: 465,
@@ -60,7 +60,7 @@ config.development = {
       pass: ""
     }
   },
-  //config for redis (register module, tryLoginTimes module)
+  // Config for redis (register module, tryLoginTimes module)
   redis: {
     default: {
       host: "127.0.0.1",