Add .drone.yml

This will automatically build and push image to the local Docker
registry

.drone.yml

@@ -0,0 +1,11 @@
+kind: pipeline
+name: build image
+
+steps:
+  - name: docker
+  image: plugins/docker
+  settings:
+    repo: registry.kucharczyk.xyz/nextcloud
+    tags: latest
+
+