[Improvement] SubmitBar: add left slot (#345)

* fix: Tabbar icon line-height

* [new feature] progress add showPivot prop

* [new feature] TabItem support vue-router

* [new feature] update document header style

* [Doc] add toast english ducoment

* [bugfix] Search box-sizing wrong

* [Doc] update vant-demo respo

* [Doc] translate theme & demo pages

* [Doc] add Internationalization document

* [bugfix] remove unnecessary props

* [fix] optimize clickoutside

* [new feature] optimize find-parent

* [new feature]: change document title accordinng to language

* [new feature] Pagination code review

* [improvement] adjust icon-font unicode

* [improvement] Icon spinner color inherit

* [improvement] icon default width

* [bugfix] DateTimePicker validate date props

* [bugfix] Tab item text ellipsis

* [improvement] optimize single line ellipsis

* [Improvement] optimzie staticClass

* [Improvement] Button: use sfc instread of jsx

* [Improvement] update actionsheet close icon style

* fix: yarn.lock

* fix: icon test cases

* [bugfix] errors during ssr

* [Improvement] SubmitBar add left slot

docs/demos/views/submit-bar.vue

@@ -33,6 +33,7 @@
         buttonText="提交订单"
         @submit="onClickButton"
       >
+        <van-checkbox v-model="checked">全选</van-checkbox>
         <span slot="tip">
           您的收货地址不支持同城送, <span class="van-edit-address" @click="onClickEditAddress">修改地址 ></span>
         </span>
@@ -52,6 +53,12 @@ export default {
     }
   },
 
+  data() {
+    return {
+      checked: true
+    };
+  },
+
   methods: {
     onClickButton() {
       Toast('点击按钮');
@@ -69,8 +76,13 @@ export default {
   .van-submit-bar {
     position: relative;
   }
+
   .van-edit-address {
     color: #38F;
   }
+
+  .van-checkbox {
+    margin-left: 15px;
+  }
 }
 </style>