[new feature] sku组件增加图片上传功能 (#612)

* [new feature] sku组件增加图片上传功能

docs/markdown/en-US/sku.md

@@ -22,6 +22,7 @@ Vue.use(Sku);
   :reset-stepper-on-hide="resetStepperOnHide"
   :reset-selected-sku-on-hide="resetSelectedSkuOnHide"
   :disable-stepper-input="disableStepperInput"
+  :message-config="messageConfig"
   @buy-clicked="onBuyClicked"
   @add-cart="onAddCartClicked"
 />
@@ -90,6 +91,7 @@ Vue.use(Sku);
 | disable-stepper-input | Whether to disable stepper input | `Boolean` | `false` | - |
 | stepper-title | Quantity title | `String` | `Quantity` | - |
 | custom-stepper-config | Custom stepper related config | `Object` | `{}` | - |
+| message-config | Message related config | `Object` | `{}` | - |
 | get-container | Return the mount node for sku | `Function` | - | `() => HTMLElement` |
 
 ### Event
@@ -201,6 +203,26 @@ customStepperConfig: {
 }
 ```
 
+#### messageConfig Data Structure
+```javascript
+messageConfig: {
+  // the upload image callback
+  uploadImg: () => {
+    return new Promise((resolve) => {
+      setTimeout(() => resolve('https://img.yzcdn.cn/upload_files/2017/02/21/FjKTOxjVgnUuPmHJRdunvYky9OHP.jpg!100x100.jpg'), 1000);
+    });
+  },
+  // max file size (MB)
+  uploadMaxSize: 3,
+  // placehold config
+  placeholderMap: {
+    text: 'xxx',
+    tel: 'xxx',
+    ...
+  }
+}
+```
+
 #### Event Params Data Structure
 
 ```javascript

docs/markdown/zh-CN/sku.md

@@ -22,6 +22,7 @@ Vue.use(Sku);
   :reset-stepper-on-hide="resetStepperOnHide"
   :reset-selected-sku-on-hide="resetSelectedSkuOnHide"
   :disable-stepper-input="disableStepperInput"
+  :message-config="messageConfig"
   @buy-clicked="onBuyClicked"
   @add-cart="onAddCartClicked"
 />
@@ -91,6 +92,7 @@ Vue.use(Sku);
 | disable-stepper-input | 是否禁用sku中stepper的input框 | `Boolean` | `false` | - |
 | stepper-title | 数量选择组件左侧文案 | `String` | `购买数量` | - |
 | custom-stepper-config | 步进器相关自定义配置 | `Object` | `{}` | - |
+| message-config | 留言相关配置 | `Object` | `{}` | - |
 | get-container | 指定挂载的 HTML 节点 | `Function` | - | `() => HTMLElement` |
 
 ### Event
@@ -207,6 +209,26 @@ customStepperConfig: {
 }
 ```
 
+#### messageConfig Data Structure
+```javascript
+messageConfig: {
+  // 图片上传回调，需要返回一个promise，promise正确执行的结果需要是一个图片url
+  uploadImg: () => {
+    return new Promise((resolve) => {
+      setTimeout(() => resolve('https://img.yzcdn.cn/upload_files/2017/02/21/FjKTOxjVgnUuPmHJRdunvYky9OHP.jpg!100x100.jpg'), 1000);
+    });
+  },
+  // 最大上传体积 (MB)
+  uploadMaxSize: 3,
+  // placehold配置
+  placeholderMap: {
+    text: 'xxx',
+    tel: 'xxx',
+    ...
+  }
+}
+```
+
 #### 添加购物车和点击购买回调函数接收的 skuData 对象结构
 ```javascript
 skuData: {