set up gitlab sync

Author: Aleyna-B

.github/workflows/sync.yml

@@ -0,0 +1,18 @@
+name: Sync to GitLab
+
+on:
+  push:
+    branches:
+      - main  
+
+jobs:
+  sync:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 0 # Important for mirroring history
+      - name: Mirror to GitLab
+        run: |
+          git remote add gitlab https://oauth2:${{ secrets.GITLAB_TOKEN }}@${{ secrets.GITLAB_REPO_URL | replace('https://', '') }}
+          git push --force --prune gitlab +refs/remotes/origin/*:refs/heads/* +refs/tags/*:refs/tags/*

.gitlab-ci.yml

@@ -0,0 +1,13 @@
+# This tells the runner which Docker image to start
+image: openjdk:latest
+
+# The 'stages' block defines the order of work
+stages:
+  - test
+
+# This is our first job
+verify-java-job:
+  stage: test
+  script:
+    - java -version
+    - echo "Hello from gitlab-runner-one! The 'Kitchen' is open."