doc: mention Taskwarrior 3 in taskserver module docs & in release notes

nixos/doc/manual/release-notes/rl-2411.section.md

@@ -27,6 +27,8 @@
 
 ## New Services {#sec-release-24.11-new-services}
 
+- [TaskChampion Sync-Server](https://github.com/GothenburgBitFactory/taskchampion-sync-server), a [Taskwariror 3](https://taskwarrior.org/docs/upgrade-3/) sync server, replacing Taskwarrior 2's sync server named [`taskserver`](https://github.com/GothenburgBitFactory/taskserver).
+
 - [FlareSolverr](https://github.com/FlareSolverr/FlareSolverr), proxy server to bypass Cloudflare protection. Available as [services.flaresolverr](#opt-services.flaresolverr.enable) service.
 
 - [Goatcounter](https://www.goatcounter.com/), Easy web analytics. No tracking of personal data. Available as [services.goatcounter](options.html#opt-services.goatcocunter.enable).

nixos/modules/services/misc/taskserver/default.md

@@ -4,6 +4,16 @@ Taskserver is the server component of the now deprecated version 2 of
 [Taskwarrior](https://taskwarrior.org/), a free and
 open source todo list application.
 
+[Taskwarrior 3.0.0 was released in March
+2024](https://github.com/GothenburgBitFactory/taskwarrior/releases/tag/v3.0.0),
+and the sync functionality was rewritten entirely. With it, a NixOS module
+named
+[`taskchampion-sync-server`](options.html#opt-services.taskchampion-sync-server.enable)
+was added to Nixpkgs. Many people still want to use the old [Taskwarrior
+2.6.x](https://github.com/GothenburgBitFactory/taskwarrior/releases/tag/v2.6.2),
+and Taskserver along with it. Hence this module and this documentation will
+stay here for the near future.
+
 ## Configuration {#module-services-taskserver-configuration}
 
 Taskserver does all of its authentication via TLS using client certificates,