Add build & publish on push

.drone.yml

@@ -1,10 +1,13 @@
 kind: pipeline
 type: docker
-name: default
+name: build & publish image
 
 steps:
-- name: greeting
-  image: alpine
-  commands:
-  - echo hello
-  - echo world
+- name: build & publish
+  image: plugins/docker
+  settings:
+    username:
+      from_secret: zipek_registry_username
+    password: 
+      from_secret: zipek_registry_password
+    repo: containers.zipek.cz/kamen/graphicek