update doc

docs/react/customize-theme.en-US.md

@@ -27,7 +27,7 @@ Specify the `theme` property in `package.json` file, whose value can be either a
 - example of directly specifying the custom values as an object:
 ```js
 "theme": {
-  "@primary-color": "#1DA57A",
+  "primary-color": "#1DA57A",
 },
 ```
 - example of specifying a [file path](https://github.com/ant-design/antd-init/blob/master/examples/customize-antd-theme/theme.js) to a JS file:

docs/react/customize-theme.zh-CN.md

@@ -28,7 +28,7 @@ antd 的样式使用了 [Less](http://lesscss.org/) 作为开发语言，并定
 
 ```js
 "theme": {
-  "@primary-color": "#1DA57A",
+  "primary-color": "#1DA57A",
 },
 ```