chore: update README

Author: voidint

README.md

@@ -196,6 +196,8 @@ Remove /Users/voidint/.g
 
 ## FAQ
 
+
+
 - What is the purpose of the environment variable `G_MIRROR`?
 
   Due to the restricted access to the Golang official website in mainland China, it has become difficult to query and download go versions. Therefore, the environment variable `G_MIRROR` can be used to specify one or multiple mirror sites (separated by commas) from which g will query and download available go versions. The known available mirror sites are as follows:
@@ -206,6 +208,14 @@ Remove /Users/voidint/.g
   - Huazhong University of Science and Technology: https://mirrors.hust.edu.cn/golang/
   - University of Science and Technology of China: https://mirrors.ustc.edu.cn/golang/
 
+- What URLs can be used as values for `G_MIRROR`?
+
+  `g` retrieves Go version information by parsing web pages and implements several version collectors for specific page structures. Currently supported collectors include:
+
+  - **Official Collector**: For Go official website. Any page with HTML structure identical to the Go official download page (e.g. `https://go.dev/dl/`) can use this collector. Example: `G_MIRROR=official|https://golang.google.cn/dl/`, where the part before `|` is the collector name and the part after is the target page URL.
+  - **FancyIndex Collector**: For pages rendered by Nginx FancyIndex module. Example: `G_MIRROR=fancyindex|https://mirrors.aliyun.com/golang/`.
+  - **AutoIndex Collector**: For pages rendered by Nginx AutoIndex module. Example: `G_MIRROR=autoindex|https://mirrors.ustc.edu.cn/golang/`.
+
 - What is the purpose of the environment variable `G_EXPERIMENTAL`?
 
   When the value of this environment variable is set to true, it enables all experimental features.

README_CN.md

@@ -206,6 +206,13 @@ Remove /Users/voidint/.g
   - 华中科技大学开源镜像站：https://mirrors.hust.edu.cn/golang/
   - 中国科学技术大学开源镜像站：https://mirrors.ustc.edu.cn/golang/
 
+- 哪些站点的 URL 可以作为`G_MIRROR`的值？
+  `g`通过网页解析的方式获取其中包含的 Go 版本信息，针对特定类型的网页结构实现了若干的版本采集器。目前支持的采集器包括以下几种：
+  - **Official Collector** ：Go官网采集器。只要网页 HTML 结构和 golang 官方下载页面(如`https://go.dev/dl/`)一致，都可以使用该采集器。设置示例，如`G_MIRROR=official|https://golang.google.cn/dl/`，其中，`|`之前的部分为采集器名称，之后的部分为目标页面的 URL。
+  - **FancyIndex Collector**：适用于 Nginx FancyIndex 模块渲染的网页。设置示例，如`G_MIRROR=fancyindex|https://mirrors.aliyun.com/golang/`。
+  - **AutoIndex Collector**：适用于 Nginx AutoIndex 模块渲染的网页。设置示例，如`G_MIRROR=autoindex|https://mirrors.ustc.edu.cn/golang/`。
+
+
 - 环境变量`G_EXPERIMENTAL`有什么作用？
 
   当该环境变量的值为`true`时，将**开启所有的实验特性**。