feat: add Multi-level menu

src/views/nested/menu1/index.vue

@@ -0,0 +1,12 @@
+<template>
+  <div class="app-container">
+    <p>{{$t('message.hsmenu1')}}</p>
+    <router-view v-slot="{ Component }">
+      <transition>
+        <component :is="Component" />
+      </transition>
+    </router-view>
+  </div>
+</template>
+
+

src/views/nested/menu1/menu1-1/index.vue

@@ -0,0 +1,3 @@
+<template>
+  <p style="text-indent:2em">{{$t('message.hsmenu1-1')}}</p>
+</template>

src/views/nested/menu1/menu1-2/index.vue

@@ -0,0 +1,10 @@
+<template>
+  <div>
+    <p style="text-indent:2em">{{$t('message.hsmenu1-2')}}</p>
+    <router-view v-slot="{ Component }">
+      <keep-alive>
+        <component :is="Component" />
+      </keep-alive>
+    </router-view>
+  </div>
+</template>

src/views/nested/menu1/menu1-2/menu1-2-1/index.vue

@@ -0,0 +1,3 @@
+<template>
+  <p style="text-indent:4em">{{$t('message.hsmenu1-2-1')}}</p>
+</template>

src/views/nested/menu1/menu1-2/menu1-2-2/index.vue

@@ -0,0 +1,3 @@
+<template>
+  <p style="text-indent:4em">{{$t('message.hsmenu1-2-2')}}</p>
+</template>

src/views/nested/menu1/menu1-3/index.vue

@@ -0,0 +1,3 @@
+<template>
+  <p style="text-indent:2em">{{$t('message.hsmenu1-3')}}</p>
+</template>

src/views/nested/menu2/index.vue

@@ -0,0 +1,3 @@
+<template>
+  <p class="app-container">{{$t('message.hsmenu2')}}</p>
+</template>