[Improvement] Reorganize document (#1066)

packages/badge/en-US.md

@@ -0,0 +1,51 @@
+## Badge
+
+### Install
+``` javascript
+import { Badge, BadgeGroup } from 'vant';
+
+Vue.use(Badge);
+Vue.use(BadgeGroup);
+```
+
+### Usage
+
+#### Basic Usage
+Use `active-key` prop to set index of chosen 'badge'
+
+```html
+<van-badge-group :active-key="activeKey">
+  <van-badge title="Title" @click="onClick" />
+  <van-badge title="Title" @click="onClick" info="8" />
+  <van-badge title="Title" @click="onClick" info="99" />
+  <van-badge title="Title" @click="onClick" info="199" />
+</van-badge-group>
+```
+
+``` javascript
+export default {
+  data() {
+    return {
+      activeKey: 0
+    };
+  },
+  methods: {
+    onClick(key) {
+      this.activeKey = key;
+    }
+  }
+};
+```
+
+### BadgeGroup API
+
+| Attribute | Description | Type | Default |
+|-----------|-----------|-----------|-------------|
+| active-key | Index of chosen badge | `String | Number` | `0` |
+
+### Badge API
+| Attribute | Description | Type | Default |
+|-----------|-----------|-----------|-------------|
+| title | Content | `String` | `''` |
+| info | Info Message | `String | Number` | `''` |
+| url | Link | `String` | - |