added drone file

.drone.yml

@@ -0,0 +1,30 @@
+kind: pipeline
+name: default
+trigger:
+  branch:
+    - main
+
+  event:
+    - push
+workspace:
+  path: /drone/src
+
+environment:
+  IMAGE_NAME: installer-tool
+  DOCKER_REGISTRY_URL: registry.format.hu
+
+steps:
+  - name: build demo image
+    image: plugins/docker
+    commands:
+      - cd /drone/src/
+      - docker build -t $${DOCKER_REGISTRY_URL}/$${IMAGE_NAME} -f Dockerfile .
+      - docker push $${DOCKER_REGISTRY_URL}/$${IMAGE_NAME}
+
+    when:
+      branch:
+        - main
+
+    volumes:
+      - name: docker
+        path: /var/run/docker.sock