message: [Doc] Sku: update document
diff: @@ -14,7 +14,7 @@ Vue.use(Sku);
  ```html
  <van-sku
  - v-model="showBase"
  + v-model="show"
  :sku="sku"
  :goods="goods"
  :goods-id="goodsId"
  @@ -31,11 +31,24 @@ Vue.use(Sku);
  />
  ```
  +```js
  +export default {
  + data() {
  + return {
  + show: false,
  + sku: {},
  + goods: {},
  + messageConfig: {}
  + };
  + }
  +}
  +```
  +
  ### Custom Stepper Config
  ```html
  <van-sku
  - v-model="showBase"
  + v-model="show"
  :sku="sku"
  :goods="goods"
  :goods-id="goodsId"
  @@ -52,7 +65,7 @@ Vue.use(Sku);
  ```html
  <van-sku
  - v-model="showCustomAction"
  + v-model="show"
  stepper-title="Stepper title"
  :sku="sku"
  :goods="goods"
  