!20 Specification NestOS Project Component Description File

From: @duyiwei7w 
Reviewed-by: @fu-shanqing 
Signed-off-by: @fu-shanqing

README.md

@@ -1,30 +1,36 @@
 # nestos-installer
 
 #### 介绍
-nestos-installer is a program to assist with installing NestOS.
 
-#### 软件架构
-软件架构说明
+nestos-installer is a program to assist with installing NestOS. It can do the following:
 
+* Install the operating system to a target disk, optionally customizing it
+  with an Ignition config or first-boot kernel parameters
+  ([`nestos-installer install`](docs/cmd/install.md))
+* Download and verify an operating system image for various cloud,
+  virtualization, or bare metal platforms ([`nestos-installer download`](docs/cmd/download.md))
+* List NestOS images available for download
+  ([`nestos-installer list-stream`](docs/cmd/list-stream.md))
+* Embed an Ignition config in a live ISO image to customize the running
+  system that boots from it ([`nestos-installer iso ignition`](docs/cmd/iso.md))
+* Wrap an Ignition config in an initrd image that can be appended to the
+  live PXE initramfs to customize the running system that boots from it
+  ([`nestos-installer pxe ignition`](docs/cmd/pxe.md))
 
-#### 安装教程
+The options available for each subcommand are available in the
+[Command Line Reference](docs/cmd.md) or via the `--help` option.
 
-1.  xxxx
-2.  xxxx
-3.  xxxx
-
-#### 使用说明
-
-1.  xxxx
-2.  xxxx
-3.  xxxx
+Take a look at the [Getting Started Guide](docs/getting-started.md) for more
+information regarding how to download and use `nestos-installer`.
 
 #### 参与贡献
 
-1.  Fork 本仓库
-2.  新建 Feat_xxx 分支
-3.  提交代码
-4.  新建 Pull Request
+master分支使用最新的上游版本，如果检测到上游有最新版本发布，先形成issue后再提交对应PR更新，流程如下。
+1.  提交issue
+2.  Fork 本仓库
+3.  新建 Feat_xxx 分支
+4.  提交代码
+5.  新建 Pull Request
 
 
 #### 特技