[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/panel.vue

@@ -0,0 +1,35 @@
+<template>
+  <demo-section>
+    <demo-block :title="$t('basicUsage')">
+      <van-panel :title="$t('title')" :desc="$t('desc')" :status="$t('status')">
+        <div>{{ $t('content') }}</div>
+      </van-panel>
+    </demo-block>
+
+    <demo-block :title="$t('advancedUsage')">
+      <van-panel :title="$t('title')" :desc="$t('desc')" :status="$t('status')">
+        <div>{{ $t('content') }}</div>
+        <div slot="footer">
+          <van-button size="small">{{ $t('button') }}</van-button>
+          <van-button size="small" type="danger">{{ $t('button') }}</van-button>
+        </div>
+      </van-panel>
+    </demo-block>
+  </demo-section>
+</template>
+
+<style lang="postcss">
+.demo-panel {
+  .van-panel__footer {
+    text-align: right;
+
+    .van-button {
+      margin-left: 5px;
+    }
+  }
+
+  .van-panel__content {
+    padding: 20px;
+  }
+}
+</style>