[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/switch-cell.vue

@@ -0,0 +1,45 @@
+<template>
+  <demo-section>
+    <demo-block :title="$t('basicUsage')">
+      <van-cell-group>
+        <van-switch-cell v-model="checked" :title="$t('title')" />
+      </van-cell-group>
+    </demo-block>
+
+    <demo-block :title="$t('disabled')">
+      <van-cell-group>
+        <van-switch-cell v-model="checked" disabled :title="$t('title')" />
+      </van-cell-group>
+    </demo-block>
+
+    <demo-block :title="$t('loading')">
+      <van-cell-group>
+        <van-switch-cell v-model="checked" loading :title="$t('title')" />
+      </van-cell-group>
+    </demo-block>
+  </demo-section>
+</template>
+
+<script>
+export default {
+  i18n: {
+    'zh-CN': {
+
+    },
+    'en-US': {
+      
+    }
+  },
+
+  data() {
+    return {
+      checked: true
+    };
+  }
+};
+</script>
+
+
+<style lang="postcss">
+
+</style>