chore: update doc

Author: DophinL

arch/images/8YI14nRwBHo9YBRq.png

@@ -1,10 +1,42 @@
-# GScatter
+# GScatter Web Extension
+
+GXChain web extension, which extends from [GetScatter/ScatterWebExtension](https://github.com/GetScatter/ScatterWebExtension).
+
+You can use this to manage your gxchain account, and interact with gxchain dapp.
+
+If you are a developer who want to develop dapp to interact with this extension, you can check [here](https://github.com/gxchain/gscatter-js).
+
 
-GXChain chrome extension, which extends from [GetScatter/ScatterWebExtension](https://github.com/GetScatter/ScatterWebExtension)
 
 ## Install
 
-```
-npm install
-npm start
-```
+### Way 1
+
+Chrome extension market, hasn't upload yet.
+
+
+
+### Way 2
+
+1.Click [here](https://github.com/gxchain/ScatterWebExtension/releases/latest) to download latest `build.zip`
+
+2.Go to chrome extension manage panel
+
+![img](./arch/images/8YI14nRwBHo9YBRq.png)
+
+3.Open `developer mode` and load extension
+
+![img](./arch/images/A51mYEBFBnUDS9sf.png)
+
+**load the unpacked zip in step 1**
+
+4.success
+
+![img](./arch/images/extension-logo.png)
+
+
+
+
+
+## Usage
+