doc/rl-2505: relnote security.acme changes

Author: m1cr0man

nixos/doc/manual/release-notes/rl-2505.section.md

@@ -554,6 +554,8 @@
   They are still expected to be working until future version 5.0.0, but will generate warnings in logs.
   Read the [release notes](https://www.authelia.com/blog/4.39-release-notes/) for human readable summaries of the changes.
 
+- `security.acme` now supports renewal using CSRs (Certificate Signing Request) through the options `security.acme.*.csr` and `security.acme.*.csrKey`.
+
 - `programs.fzf.keybindings` now supports the fish shell.
 
 - A toggle has been added under `users.users.<name>.enable` to allow toggling individual users conditionally. If set to false, the user account will not be created.