docs: edit .gitignore and index

* GitHub Page: https://doocs.github.io/advanced-java
* Gitee Page: https://doocs.gitee.io/advanced-java
* Author: https://github.com/yanglbme

index.html

@@ -35,14 +35,13 @@
     </ul>
     
   </nav>
-  <div id="app">Welcome to Advanced-Java</div>
+  <div id="app">本知识仓库由 Doocs 开源社区总结发布</div>
   <script>
     window.$docsify = {
       name: 'advanced-java',
       repo: 'doocs/advanced-java',
       maxLevel: 3,
       auto2top: true,
-      loadNavbar: false,
       coverpage: true,
       coverpage: 'docs/extra-page/cover.md',
       mergeNavbar: true,