added pipeline code

Jenkinsfile

@@ -0,0 +1,35 @@
+pipeline {
+    agent {label 'JDK-17'}
+    trigger{
+        pollSCM('* * * * *')
+    }
+    stages {
+        stage('vcm') {
+            steps {
+                git url : 'https://github.com/devops-Jenkins-assignment/spring-petclinic-1.git',
+                 branch : 'feature'
+            }
+        }
+        stage('Merge Pull Request') {
+            steps {
+                script {
+                    def prNumber = env.CHANGE_ID
+                    def repoOwner = env.GIT_AUTHOR_NAME 
+                    def repoName = GIT_BRANCH
+                    def targetBranch = 'develop'  
+                     echo "PR Number : ${prNumber} -repo owner : ${repoOwner} - repo Name : ${repoName}"               
+                    // clone the repository
+                    checkout([$class: 'GitSCM', branches: [[name: '*/develop']], doGenerateSubmoduleConfigurations: false, extensions: [], submoduleCfg: [], userRemoteConfigs: [[credentialsId: 'your_credentials_id', url: 'your_repo_url']]])
+                    // fetch the pull request
+                    sh "git fetch origin pull/${prNumber}/head:pr-${prNumber}"
+                    // checkout the pull request
+                    sh "git checkout pr-${prNumber}"
+                    // merge the pull request into the develop branch
+                    sh "git merge origin/${targetBranch} --no-ff --no-edit"
+                    // push the changes to the remote repository
+                    sh "git push origin ${targetBranch}"
+                }
+            }
+        }
+    }
+}