[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/dialog.vue

@@ -0,0 +1,60 @@
+<template>
+  <demo-section>
+    <demo-block :title="$t('title1')">
+      <van-button @click="onClickAlert">Alert</van-button>
+      <van-button @click="onClickAlert2">{{ $t('alert2') }}</van-button>
+    </demo-block>
+
+    <demo-block :title="$t('title2')">
+      <van-button @click="onClickConfirm">Confirm</van-button>
+    </demo-block>
+  </demo-section>
+</template>
+
+<script>
+export default {
+  i18n: {
+    'zh-CN': {
+      title1: '消息提示',
+      title2: '消息确认',
+      alert2: '无标题 Alert'
+    },
+    'en-US': {
+      title1: 'Alert dialog',
+      title2: 'Confirm dialog',
+      alert2: 'Alert without title'
+    }
+  },
+
+  methods: {
+    onClickAlert() {
+      Dialog.alert({
+        title: this.$t('title'),
+        message: this.$t('content')
+      });
+    },
+
+    onClickAlert2() {
+      Dialog.alert({
+        message: this.$t('content')
+      });
+    },
+
+    onClickConfirm() {
+      Dialog.confirm({
+        title: this.$t('title'),
+        message: this.$t('content')
+      })
+    }
+  }
+};
+</script>
+
+
+<style lang="postcss">
+.demo-dialog {
+  .van-button {
+    margin: 15px;
+  }
+}
+</style>