Add the Gogs webhook template URL

Guides/jenkins.md

@@ -49,6 +49,14 @@ Install `gogs-webhook` plugin.
 
 Documentation on [plugins.jenkins.io](https://plugins.jenkins.io/gogs-webhook).
 
+#### Add webhook on Gogs side
+
+In the Gogs repository settings, add the _webhook_
+
+`https://jenkins.jovian-hersemeule.eu/gogs-webhook/?job=experiments/connect`
+
+Adapt job name.
+
 #### Private communication
 
 - Create a Jenkins account on Gogs