chore(docs): Update machine-learning.md

docs/docs/guides/machine-learning.md

@@ -2,7 +2,7 @@
 
 To alleviate [performance issues on low-memory systems](/docs/FAQ.md#why-is-immich-slow-on-low-memory-systems-like-the-raspberry-pi) like the Raspberry Pi, you may also host Immich's machine-learning container on a more powerful system (e.g. your laptop or desktop computer):
 
-- Set `IMMICH_MACHINE_LEARNING_URL` to point to the designated ML system, e.g. `http://workstation:3003`.
+- Set the URL in Machine Learning Settings on the Admin Settings page to point to the designated ML system, e.g. `http://workstation:3003`.
 - Copy the following `docker-compose.yml` to your ML system.
 - Start the container by running `docker-compose up -d` or `docker compose up -d` (depending on your Docker version).