Update Jenkinsfile to test webhook

Jenkinsfile

@@ -1 +1,12 @@
-pipeline {\n    agent any\n    stages {\n        stage("Hello") {\n            steps {\n                echo "Hello from Gitea + Jenkins CI\!"\n                echo "Build triggered by webhook"\n            }\n        }\n    }\n}
+pipeline {
+    agent any
+    stages {
+        stage("Build") {
+            steps {
+                echo "Hello from Gitea + Jenkins CI"
+                echo "Webhook trigger is working"
+                sh "date"
+            }
+        }
+    }
+}