[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/common.js

@@ -0,0 +1,72 @@
+/**
+ * Demo Common Mixin && i18n
+ */
+
+import Vue from 'vue';
+import { Locale, Toast, Dialog } from 'packages';
+import { DemoBlock, DemoSection } from 'vant-doc';
+import camelize from 'packages/utils/camelize';
+
+const demoBaseMixin = {
+  beforeCreate() {
+    const { name, i18n } = this.$options;
+    if (name && i18n) {
+      const formattedI18n = {};
+      const camelizedName = camelize(name);
+      Object.keys(i18n).forEach(key => {
+        formattedI18n[key] = { [camelizedName]: i18n[key] };
+      });
+      Locale.add(formattedI18n);
+    }
+  }
+};
+
+window.Toast = Toast;
+window.Dialog = Dialog;
+Vue.mixin(Locale.i18n);
+Vue.mixin(demoBaseMixin);
+Vue.component('demo-block', DemoBlock);
+Vue.component('demo-section', DemoSection);
+
+Locale.add({
+  'zh-CN': {
+    red: '红色',
+    orange: '橙色',
+    yellow: '黄色',
+    tab: '标签',
+    tag: '标签',
+    desc: '描述信息',
+    back: '返回',
+    title: '标题',
+    status: '状态',
+    button: '按钮',
+    option: '选项',
+    search: '搜索',
+    content: '内容',
+    custom: '自定义',
+    loading: '加载状态',
+    disabled: '禁用状态',
+    basicUsage: '基础用法',
+    advancedUsage: '高级用法'
+  },
+  'en-US': {
+    red: 'Red',
+    orange: 'Orange',
+    yellow: 'Yellow',
+    tab: 'Tab',
+    tag: 'Tag',
+    desc: 'Description',
+    back: 'Back',
+    title: 'Title',
+    status: 'Status',
+    button: 'Button',
+    option: 'Option',
+    search: 'Search',
+    content: 'Content',
+    custom: 'Custom',
+    loading: 'Loading',
+    disabled: 'Disabled',
+    basicUsage: 'Basic Usage',
+    advancedUsage: 'Advanced Usage'
+  }
+});