[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/number-keyboard.vue

@@ -0,0 +1,59 @@
+<template>
+  <demo-section>
+    <demo-block :title="$t('basicUsage')">
+      <van-button @touchstart.native.stop="showKeyboard = true">
+        {{ $t('button1') }}
+      </van-button>
+
+      <van-button @touchstart.native.stop="showKeyboard = false">
+        {{ $t('button2') }}
+      </van-button>
+
+      <van-number-keyboard
+        :show="showKeyboard"
+        @blur="showKeyboard = false"
+        @input="onInput"
+        @delete="onDelete"
+      />
+    </demo-block>
+  </demo-section>
+</template>
+
+<script>
+export default {
+  i18n: {
+    'zh-CN': {
+      button1: '弹出键盘',
+      button2: '收起键盘'
+    },
+    'en-US': {
+      button1: 'Show Keyboard',
+      button2: 'Hide Keyboard'
+    }
+  },
+
+  data() {
+    return {
+      showKeyboard: true
+    };
+  },
+
+  methods: {
+    onInput(value) {
+      Toast('Input: ' + value);
+    },
+    onDelete() {
+      Toast('Delete');
+    }
+  }
+}
+</script>
+
+
+<style lang="postcss">
+.demo-number-keyboard {
+  .van-button {
+    margin-left: 15px;
+  }
+}
+</style>