docs: fix example doc

Author: LandJerry

docs/guidebook/en/1_Run_the_first_example.md

@@ -153,8 +153,8 @@ You need to apply for the SERPER_API_KEY on the official Serper website and conf
 After applying, find the corresponding key in the custom_key.toml configuration file and uncomment it as shown.
 
 ```toml
-##search api
-SEARCHAPI_API_KEY='key_xxxxxx'
+#Google search
+SERPER_API_KEY='xxxxxx'
 ```
 
 Follow the steps in Section 2 to execute other cases. You can now reference and run all official cases.

docs/guidebook/zh/1_运行第一个教程案例.md

@@ -157,8 +157,8 @@ Tips：为简化配置过程，这里我们只列举了部分常用模型服务
 申请完成后，在密钥配置文件 custom_key.toml 中找到对应的key填写，并放开注释如下：
 
 ```toml
-##search api
-SEARCHAPI_API_KEY='key_xxxxxx'
+#Google search
+SERPER_API_KEY='xxxxxx'
 ```
 
 按照第2部分的步骤执行其他案例即可，现在您可以运行所有官方案例了。