[new feature] add i18n support (#310)

* 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

* [new feature] add i18n support

* feat: Extract demos from markdown

* feat: Base components demos

* [new feature] complete demo extract & translate

* [fix] text cases

* fix: add deepAssign test cases

* fix: changelog detail

* [new feature] AddressEdit support i18n

docs/demos/views/datetime-picker.vue

@@ -0,0 +1,61 @@
+<template>
+  <demo-section>
+    <demo-block :title="$t('basicUsage')">
+      <van-datetime-picker
+        v-model="currentDate1"
+        type="datetime"
+        :minHour="minHour"
+        :maxHour="maxHour"
+        :minDate="minDate"
+        :maxDate="maxDate"
+      />
+    </demo-block>
+
+    <demo-block :title="$t('title2')">
+      <van-datetime-picker
+        v-model="currentDate2"
+        type="date"
+        :minHour="minHour"
+        :maxHour="maxHour"
+        :minDate="minDate"
+      />
+    </demo-block>
+
+    <demo-block :title="$t('title3')">
+      <van-datetime-picker
+        v-model="currentDate3"
+        type="time"
+        :minHour="minHour"
+        :maxHour="maxHour"
+        :minDate="minDate"
+      />
+    </demo-block>
+  </demo-section>
+</template>
+
+<script>
+export default {
+  i18n: {
+    'zh-CN': {
+      title2: '选择日期',
+      title3: '选择时间'
+    },
+    'en-US': {
+      title2: 'Date Picker',
+      title3: 'Time Picker'
+    }
+  },
+
+  data() {
+    return {
+      minHour: 10,
+      maxHour: 20,
+      minDate: new Date(),
+      maxDate: new Date(2019, 10, 1),
+      currentDate1: new Date(2018, 0, 1),
+      currentDate2: null,
+      currentDate3: null
+    };
+  }
+};
+</script>