[docs] add zh docs (#3507)

* [docs] add zh docs

* [docs] add lang dropdown

* [docs] update mkdocs zh config

* [docs] migrate assets

* [docs] update overrides dir in mkdocs zh config

* [docs] exclude locales director in main mkdocs config

* [docs] rename assets to public to avoid conflicting with template

* [docs] extra_css change followup

* [docs] add theme.palette.toggle.icon back into mkdocs zh config

* [docs] fix zh readme reference + migrate language-specific repo markdown to docs

* [docs] translate remaining repo docs + update reference

* [docs] update zh index.md reference

* [docs/zh] wording alignment

docs/locales/zh/configuration/web.md

@@ -0,0 +1,21 @@
+# Web
+
+## 设置
+
+```yaml
+######################
+##### WEB CONFIG #####
+######################
+
+# 与网页模板和发送邮件通知等相关的配置
+
+# 字符串。GoToSocial 尝试加载 HTML 模板 (.tmpl 文件) 的目录。
+# 示例: ["/some/absolute/path/", "./relative/path/", "../../some/weird/path/"]
+# 默认值: "./web/template/"
+web-template-base-dir: "./web/template/"
+
+# 字符串。GoToSocial 试图提供静态网页资源（图片，脚本）的目录。
+# 示例: ["/some/absolute/path/", "./relative/path/", "../../some/weird/path/"]
+# 默认值: "./web/assets/"
+web-asset-base-dir: "./web/assets/"
+```