[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/password-input.vue

@@ -0,0 +1,47 @@
+<template>
+  <demo-section>
+    <demo-block :title="$t('basicUsage')">
+      <van-password-input
+        :value="value"
+        :info="$t('info')"
+        @focus="showKeyboard = true"
+      />
+
+      <van-number-keyboard
+        :show="showKeyboard"
+        @input="onInput"
+        @delete="onDelete"
+        @blur="showKeyboard = false"
+      />
+    </demo-block>
+  </demo-section>
+</template>
+
+<script>
+export default {
+  i18n: {
+    'zh-CN': {
+      info: '密码为 6 位数字'
+    },
+    'en-US': {
+      info: 'Some tips'
+    }
+  },
+
+  data() {
+    return {
+      value: '',
+      showKeyboard: true
+    };
+  },
+
+  methods: {
+    onInput(key) {
+      this.value = (this.value + key).slice(0, 6);
+    },
+    onDelete() {
+      this.value = this.value.slice(0, this.value.length - 1);
+    }
+  }
+};
+</script>