ci: use docker plugin for drone

.drone.yml

@@ -4,13 +4,18 @@ type: docker
 name: caddy-build-deploy
 
 steps:
-  - name: podman-build
-    image:
+  - name: build-and-push-image
+    image: plugins/docker
     volumes:
       - name: docker-sock
         path: /run/podman/podman.sock
-    commands:
-      - podman build -t registry.meatbag.se/meatbag/murmur .
+    settings:
+      username: meatbag
+      password:
+        from_secret: registry_password
+      repo: meatbag/caddy
+      tags: latest
+      dockerfile: Dockerfile
 
 trigger:
   branch: