docs(slot): 修改自定义模板文档和演示，解决 iframe 页签无法通过按钮关闭

fix bhuh12#14

Author: bhuh12

demo/components/layout/Slot.vue

@@ -7,12 +7,12 @@
           class="tab-icon"
           :class="icon"
         />
-        <span class="tab-title">{{ title || '未命名页签' }}</span>
+        <span class="tab-title">{{ $routerTab.i18nText(title) || '未命名页签' }}</span>
         <span class="tab-badge">{{ index }}</span>
         <i
-          v-if="closable !== false &&tabs.length > 1"
-          class="tab-close el-icon-close"
-          @click.prevent="$routerTab.close(id)"
+          v-if="closable !== false && tabs.length > 1"
+          class="tab-close"
+          @click.prevent="$routerTab.closeTab(id)"
         />
       </template>
     </router-tab>

docs/guide/advanced/slot.md

@@ -14,10 +14,18 @@
 ``` html {2}
 <router-tab>
   <template v-slot="{ tab: { id, title, icon, closable }, tabs, index}">
-    <i v-if="icon" class="tab-icon" :class="icon"></i>
-    <span class="tab-title">{{title || '未命名页签'}}</span>
-    <span class="tab-badge">{{index}}</span>
-    <i class="tab-close el-icon-close" v-if="closable !== false &&tabs.length > 1" @click.prevent="$routerTab.close(id)"></i>
+    <i
+      v-if="icon"
+      class="tab-icon"
+      :class="icon"
+    />
+    <span class="tab-title">{{ $routerTab.i18nText(title) || '未命名页签' }}</span>
+    <span class="tab-badge">{{ index }}</span>
+    <i
+      v-if="closable !== false && tabs.length > 1"
+      class="tab-close"
+      @click.prevent="$routerTab.closeTab(id)"
+    />
   </template>
 </router-tab>
 ```