update:rewrite Carousel.vue and NavMenu,vue

wj-vue/src/components/common/NavMenu.vue

 <template>
   <div>
     <el-menu
-      :default-active="this.$router.path"
+      :default-active="'/appindex'"
       router="true"
       mode="horizontal"
       @select="handleSelect"

wj-vue/src/components/home/Carousel.vue

 <template>
   <el-carousel :interval="4000" type="card" height="300px" arrow="always" style="padding: 20px 5px">
     <el-carousel-item v-for="item in items" :key="item" style="box-shadow: 10px 10px 5px #888888;">
-      <a href="">
+      <a :href=item.link target="_Blank">
         <img :src=item.img alt="" class="carousel_img">
       </a>
       <h3>{{item.title}}</h3>
@@ -39,18 +39,18 @@
     data: function () {
       return {
         items: [{
-          title: 'How2J 学习网站',
+          title: 'How2J.cn',
           img: '../../../static/img/carousel/how2j.png',
-          link: 'link1'},
+          link: 'http://how2j.cn?p=50613'},
         {
           title: 'Vue',
           img: '../../../static/img/carousel/vue.png',
-          link: 'link1'
+          link: 'https://cn.vuejs.org/'
         },
         {
           title: 'element-ui',
           img: '../../../static/img/carousel/element.png',
-          link: 'link1'
+          link: 'http://element-cn.eleme.io/#/zh-CN'
         }]
       }
     }