Fix broken links (#1)

- Always use a relative markdown link so that we can jump even if we edit it in local env or read it in code hosting server.

Reviewed-on: https://gitea.com/gitea/docs/pulls/1

versioned_docs/version-1.22/administration/fail2ban-setup.md

@@ -119,7 +119,7 @@ proxy_set_header X-Real-IP $remote_addr;
 
 The security options in `app.ini` need to be adjusted to allow the interpretation of the headers
 as well as the list of IP addresses and networks that describe trusted proxy servers
-(See the [configuration cheat sheet](administration/config-cheat-sheet.md#security-security) for more information).
+(See the [configuration cheat sheet](../administration/config-cheat-sheet.md#security-security) for more information).
 
 ```
 REVERSE_PROXY_LIMIT = 1