[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/popup.vue

@@ -0,0 +1,112 @@
+<template>
+  <demo-section>
+    <demo-block :title="$t('basicUsage')">
+      <van-button @click="show1 = true">{{ $t('button1') }}</van-button>
+      <van-popup v-model="show1">{{ $t('content') }}</van-popup>
+    </demo-block>
+
+    <demo-block :title="$t('position')">
+      <van-button @click="show2 = true;">{{ $t('button2') }}</van-button>
+      <van-popup v-model="show2" position="bottom">
+        <van-button @click="showDialog">{{ $t('button3') }}</van-button>
+      </van-popup>
+
+      <van-button @click="show3 = true">{{ $t('button4') }}</van-button>
+      <van-popup v-model="show3" position="top" :overlay="false">
+        {{ $t('content') }}
+      </van-popup>
+
+      <van-button @click="show4 = true">{{ $t('button5') }}</van-button>
+      <van-popup v-model="show4" position="right" :overlay="false">
+        <van-button @click="show4 = false">{{ $t('button6') }}</van-button>
+      </van-popup>
+    </demo-block>
+  </demo-section> 
+</template>
+
+<script>
+export default {
+  i18n: {
+    'zh-CN': {
+      position: '弹出位置',
+      button1: '弹出 Popup',
+      button2: '底部弹出',
+      button3: '弹出 Dialog',
+      button4: '顶部弹出',
+      button5: '右侧弹出',
+      button6: '关闭弹层'
+    },
+    'en-US': {
+      position: 'Position',
+      button1: 'Show Popup',
+      button2: 'From Bottom',
+      button3: 'Show Dialog',
+      button4: 'From Top',
+      button5: 'From Right',
+      button6: 'Close Popup'
+    }
+  },
+
+  data() {
+    return {
+      show1: false,
+      show2: false,
+      show3: false,
+      show4: false
+    }
+  },
+
+  watch: {
+    show3(val) {
+      if (val) {
+        setTimeout(() => {
+          this.show3 = false;
+        }, 2000);
+      }
+    }
+  },
+
+  methods: {
+    showDialog() {
+      Dialog.confirm({
+        title: 'confirm标题',
+        message: '弹窗提示文字，左右始终距离边20PX，上下距离20PX，文字左对齐。弹窗提示文字，左右始终距离边20PX，上下距离20PX，文字左对齐。'
+      })
+    }
+  }
+};
+</script>
+
+<style lang="postcss">
+.demo-popup {
+  .van-button {
+    margin: 10px 0 10px 15px;
+  }
+
+  .van-popup {
+    width: 60%;
+    padding: 20px;
+    border-radius: 5px;
+    box-sizing: border-box;
+
+    &--bottom {
+      width: 100%;
+      height: 200px;
+    }
+
+    &--top {
+      color: #fff;
+      width: 100%;
+      border-radius: 0;
+      line-height: 20px;
+      background-color: rgba(0, 0, 0, 0.8);
+    }
+
+    &--left,
+    &--right {
+      width: 100%;
+      height: 100%;
+    }
+  }
+}
+</style>