编辑器-选择素材窗口：没有三维场景时可跳转到首页

(cherry picked from commit efb2bb6900d05d38331616631b50d7c613293882)

packages/qjkankan-editor/src/components/materialSelectorForEditor.vue

@@ -263,6 +263,9 @@
         <div v-if="!latestUsedSearchKey">
           <img :src="require('@/assets/images/default/empty_04.png')" alt="">
           <span>{{'暂无素材~'}}</span>
+          <a href="/#/">
+            <button class="ui-button">如何拍摄三维场景</button>
+          </a>
         </div>
       </div>
     </div>
@@ -779,6 +782,11 @@ export default {
         font-size: 14px;
         color: rgba(255, 255, 255, 0.6);
       }
+      > a {
+        > button {
+          margin-top: 20px;
+        }
+      }
     }
   }
 }