nixos/doc/rl-2505: mention boot.kernel.sysfs addition

Author: illdefined

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

@@ -92,6 +92,8 @@
 
 - [MaryTTS](https://github.com/marytts/marytts), an open-source, multilingual text-to-speech synthesis system written in pure Java. Available as [services.marytts](options.html#opt-services.marytts).
 
+- [boot.kernel.sysfs](options.html#opt-boot.kernel.sysfs) allows setting of sysfs attributes.
+
 - [networking.modemmanager](options.html#opt-networking.modemmanager) has been split out of [networking.networkmanager](options.html#opt-networking.networkmanager). NetworkManager still enables ModemManager by default, but options exist now to run NetworkManager without ModemManager.
 
 - [Routinator 3000](https://nlnetlabs.nl/projects/routing/routinator/), a full-featured RPKI Relying Party software package that runs as a service which periodically downloads and verifies RPKI data.