[Doc] update quickstart.md

docs/markdown/quickstart.en-US.md

@@ -10,34 +10,26 @@ npm install -g @vue/cli
 
 # Create a project
 vue create hello-world
-```
 
-After the creation is complete, you can open the GUI by command.
-
-```bash
 # Open GUI
 vue ui
 ```
 
-In the GUI, click on 'Dependencies' -> `Install Dependencies` and add `vant` to the dependencies.
+<img width="100%" style="border-radius: 3px; box-shadow: 0 1px 1px rgba(0, 0, 0, .1);" src="https://img.yzcdn.cn/vant/vue-cli-demo-201809030812.png" >
 
-<img width="100%" style="box-shadow: 0 1px 1px rgba(0, 0, 0, .1); border-radius: 3px;" src="https://img.yzcdn.cn/vant/vue-cli-demo-201809030812.png" >
+In the GUI, click on 'Dependencies' -> `Install Dependencies` and add `vant` to the dependencies.
 
 ### Install
 
-#### NPM
-
-```shell
+```bash
+# npm
 npm i vant -S
-```
 
-#### YARN
-
-```shell
+# yarn
 yarn add vant
 ```
 
-#### CDN
+### CDN
 
 ```html
 <!-- import style -->
@@ -48,12 +40,14 @@ yarn add vant
 <script src="https://cdn.jsdelivr.net/npm/vant@1.6/lib/vant.min.js"></script>
 ```
 
-### Usage
+## Usage
 
-#### 1. Use [babel-plugin-import](https://github.com/ant-design/babel-plugin-import) (Recommended)
+### 1. Import on demand
+
+Use [babel-plugin-import](https://github.com/ant-design/babel-plugin-import) to import components on demand
 
 ```bash
-# Install babel-plugin-import
+# Install plugin
 npm i babel-plugin-import -D
 ```
 
@@ -82,22 +76,21 @@ module.exports = {
 };
 ```
 
-Then you can import components from vant, equivalent to import manually below.
-
 ```js
+// Then you can import components from vant
 import { Button } from 'vant';
 ```
 
 > If you are using TypeScript，please use [ts-import-plugin](https://github.com/Brooooooklyn/ts-import-plugin) instead
 
-#### 2. Manually import
+### 2. Manually import
 
 ```js
 import Button from 'vant/lib/button';
 import 'vant/lib/button/style';
 ```
  
-#### 3. Import all components
+### 3. Import all components
 
 ```js
 import Vue from 'vue';
@@ -109,6 +102,7 @@ Vue.use(Vant);
 
 > If you configured babel-plugin-import, you won't be allowed to import all components.
 
+## Other
 
 ### Rem units