add more introduction in readme

README.md

@@ -9,6 +9,24 @@
 
 [中文版README](https://github.com/aliyun/aliyun-log-cli/blob/master/README_CN.md)
 
+## Backgroud
+
+The Alicloud log service provides with Web and SDK flavor to operate log service and analyzie logs. To make it more convinient to do automation, we release this command line interface (CLI).
+
+### Introduction
+
+Alicloud log service command line console, support almost all operations as web. It also supports incomplete log query check and query cross multiple pages. It could even do project settings copy cross multiple regions.
+
+### Major Features
+
+- Support almost all 50+ REST API of log service. 
+- Multiple account support to support cross region operation.
+- Log query incomplete check and automatically query cross pagination. 
+- Multiple confidential storage types, from file, commandline to env variables.
+- Support command line based or file based inputs, complete formation validations.
+- Support JMES filter to do further process on results, e.g. select specific fields from json. 
+- Cross platforms support (Windows, Linux and Mac), Python based and friendly to Py2 and Py3 even Pypy. Support Pip installation.
+
 
 ### Installation
 

README_CN.md

@@ -9,6 +9,24 @@
 
 [README in English](https://github.com/aliyun/aliyun-log-cli/blob/master/README.md)
 
+
+## 背景
+一直以来日志服务(SLS)提供了Web和SDK的方式进行日志采集, 管理, 查询和分析. 为了方便用户越来越多的的自动化日志配置查询分析的需求, 我们重磅发布了SLS的命令行控制台(Command Line Interface - CLI).
+
+### 基本介绍
+SLS命令行控制台, 支持几乎所有操作, 日志查询支持完整性检查与自动分页, 支持多账户与跨域复制.
+
+### 主要功能
+
+- 支持几乎所有50多个日志服务的REST接口.
+- 支持多账号, 方便测试与跨域操作.
+- 日志查询完整性查询与自动分页.
+- 支持多种方式存储和配置秘钥, 适用于各种情况.
+- 支持通过命令行或者文件的形式输入复杂参数, 并校验参数内容格式.
+- 支持JMES过滤器对结果进行进一步处理, 方便选择特定信息.
+- 跨平台(Windows/Linux和Mac)支持, 基于Python(Py2.6+和Py3.3+平台友好)，支持Pip安装。
+
+
 ### 安装
 
 ```shell