docs(core): update guide for cache-debugging (#1028)

Author: yuyutaotao

apps/site/docs/en/caching.mdx

@@ -105,4 +105,8 @@ Midscene uses [XPath](https://developer.mozilla.org/en-US/docs/Web/XML/XPath) to
 1. The text content of the new element at the same XPath is different from the cached element.
 2. The DOM structure of the page is changed from the cached one.
 
-When the cache is not hit, the process will fall back to continue using AI services to find the element.
+When the cache is not hit, the process will fall back to continue using AI services to find the element.
+
+### Get more debug logs for caching
+
+You can set the `DEBUG=midscene:cache:*` environment variable to get more debug logs for caching.

apps/site/docs/zh/caching.mdx

@@ -107,4 +107,8 @@ Midscene 使用 [XPath](https://developer.mozilla.org/en-US/docs/Web/XML/XPath)
 1. 新元素在相同的 XPath 下的文本内容与缓存元素不同。
 2. 页面的 DOM 结构与缓存时的结构不同。
 
-当缓存未命中时，Midscene 将回退到继续使用 AI 服务来查找元素。
+当缓存未命中时，Midscene 将回退到继续使用 AI 服务来查找元素。
+
+### 获取缓存相关的调试日志
+
+在环境变量中配置 `DEBUG=midscene:cache:*`，你可以看到缓存相关的调试日志。