fix(VPSidebarItem): use depth and index as the key

src/client/theme-default/components/VPSidebarItem.vue

@@ -97,8 +97,8 @@ function onCaretClick() {
     <div v-if="item.items && item.items.length" class="items">
       <template v-if="depth < 5">
         <VPSidebarItem
-          v-for="i in item.items"
+          v-for="(i, j) in item.items"
-          :key="i.text"
+          :key="`${depth}-${j}`"
           :item="i"
           :depth="depth + 1"
         />