message: docs(Tag): fix closeable demo
diff: @@ -73,17 +73,19 @@ Vue.use(Tag);
  ```html
  <van-tag
  - v-if="showPrimary"
  - type="primary"
  + v-if="show.primary"
  + closeable
  size="medium"
  + type="primary"
  @close="close('primary')"
  >
  Tag
  </van-tag>
  <van-tag
  - v-if="showSuccess"
  - type="success"
  + v-if="show.success"
  + closeable
  size="medium"
  + type="success"
  @close="close('success')"
  >
  Tag
  