Add CI file

.gitlab-ci.yml

+container-registry:
+  image: docker:24.0.1
+  services:
+    - docker:24.0.1-dind
+  variables:
+    IMAGE_TAG: $CI_REGISTRY_IMAGE:$CI_COMMIT_REF_SLUG
+    DOCKER_HOST: tcp://docker:2376
+    DOCKER_TLS_CERTDIR: "/certs"
+    DOCKER_TLS_VERIFY: 1
+    DOCKER_CERT_PATH: "$DOCKER_TLS_CERTDIR/client"
+  before_script:
+    - |
+      echo "Waiting for docker to start..."
+      for i in $(seq 1 30); do
+        docker info && break
+        sleep 1s
+      done
+  script:
+    - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
+    - docker build -t $IMAGE_TAG .
+    - docker push $IMAGE_TAG