config: update ip rule page

docs/config/ip-rule.md

@@ -25,6 +25,8 @@ whitelist-ip 192.168.1.1/24
 
 ## 黑名单IP地址
 
+如下想对某个上游限制其返回的IP地址，将指定范围的IP丢弃，则可设置黑名单如下：
+
 ```shell
 server -blacklist-ip
 blacklist-ip 192.168.1.1/24

en/docs/config/ip-rule.md

@@ -25,6 +25,8 @@ whitelist-ip 192.168.1.1/24
 
 ## Blacklist IP addresses
 
+To restrict the return of IP addresses from a certain upstream and discard IP within a specified range, a blacklist can be set up as follows:
+
 ```shell
 server -blacklist-ip
 blacklist-ip 192.168.1.1/24