docs: update cicd runner setup docs

docs/developer/cicd_runner.md

@@ -13,21 +13,28 @@ Resources:
  - https://docs.gitea.com/usage/actions/act-runner
  - https://linux.psi.ch/documentation/services/gitea/gitea-runner/
 
-TODO: add commands we ran with Basil in the meeting
-TODO: need to regenerate `~/gitea-runner/.runner` with correct label `hla-dev`
-
-```shell
-<install command>
+Register the runner: (by default the name is the machine name `sls-vserv-bd-hla01-dev.psi.ch`)
+```
 sudo su svcusr-sls2hla
+mkdir ~/gitea-runner
+cd ~/gitea-runner
+/usr/local/bin/act_runner register --instance https://gitea.psi.ch/ --labels hla-dev --token <token> --no-interactive
+```
 
-# Set up hla deployment dir
+This generates a `.runner` file.
+
+
+Set up deployment dirs (not directly related to the gitea cicd runner setup)
+```shell
 mkdir /sls/bd/hla
 chmod 755 /sls/bd/hla
 ...
+```
 
+Install Node -- required for actions like repo checkout
+```
 mkdir ~/.local/bin
 
-# Install Node -- required for actions like repo checkout
 cd /tmp
 curl -LO https://nodejs.org/dist/v20.11.1/node-v20.11.1-linux-x64.tar.xz
 tar -xf node-v20.11.1-linux-x64.tar.xz --strip-components=2 -C ~/.local/bin/ node-v20.11.1-linux-x64/bin/
@@ -119,6 +126,15 @@ sudo su svcusr-sls2hla
 journalctl -u act_runner.service -n 20
 ```
 
+Should show 
+
+```
+Jul 24 10:05:30 sls-vserv-bd-hla01-dev.psi.ch act_runner[3662214]: time="2026-07-24T10:05:30+02:00" level=info msg="Starting runner daemon"
+Jul 24 10:05:30 sls-vserv-bd-hla01-dev.psi.ch act_runner[3662214]: time="2026-07-24T10:05:30+02:00" level=info msg="labels updated to: [hla-dev:host]"
+Jul 24 10:05:30 sls-vserv-bd-hla01-dev.psi.ch act_runner[3662214]: time="2026-07-24T10:05:30+02:00" level=info msg="runner: sls-vserv-bd-hla01-dev.psi.ch, with version: v2.0.0, with labels: [hla-dev], declare successfully"
+...
+```
+
 ## User
 
 The gitea actions run as user `svcusr-sls2hla`