Docusaurus-ify (#26051)

This PR cleans up the docs in a way to make them simpler to ingest by
our [docs repo](https://gitea.com/gitea/gitea-docusaurus).

1. It includes all of the sed invocations our ingestion did, removing
the need to do it at build time.
2. It replaces the shortcode variable replacement method with
`@variable@` style, simply for easier sed invocations when required.
3. It removes unused files and moves the docs up a level as cleanup.

---------

Signed-off-by: jolheiser <john.olheiser@gmail.com>

docs/content/administration/search-engines-indexation.zh-cn.md

@@ -0,0 +1,39 @@
+---
+date: "2023-05-23T09:00:00+08:00"
+title: "搜索引擎索引"
+slug: "search-engines-indexation"
+sidebar_position: 60
+toc: false
+draft: false
+aliases:
+  - /zh-cn/search-engines-indexation
+menu:
+  sidebar:
+    parent: "administration"
+    name: "搜索引擎索引"
+    sidebar_position: 60
+    identifier: "search-engines-indexation"
+---
+
+# Gitea 安装的搜索引擎索引
+
+默认情况下，您的 Gitea 安装将被搜索引擎索引。
+如果您不希望您的仓库对搜索引擎可见，请进一步阅读。
+
+## 使用 robots.txt 阻止搜索引擎索引
+
+为了使 Gitea 为顶级安装提供自定义的`robots.txt`（默认为空的 404），请在[`custom`文件夹或`CustomPath`]（administration/customizing-gitea.md）中创建一个名为 `robots.txt` 的文件。
+
+有关如何配置 `robots.txt` 的示例，请参考 [https://moz.com/learn/seo/robotstxt](https://moz.com/learn/seo/robotstxt)。
+
+```txt
+User-agent: *
+Disallow: /
+```
+
+如果您将Gitea安装在子目录中，则需要在顶级目录中创建或编辑 `robots.txt`。
+
+```txt
+User-agent: *
+Disallow: /gitea/
+```