Update '.drone.yml'

.drone.yml

@@ -16,6 +16,20 @@ steps:
     - ls /drone/src/AOC2021.Test/bin/Debug/net5.0/
     - dotnet test AOC2021.Test --logger "console;verbosity=detailed"
 
+- name: build-aoc-2021-2
+  image: plugins/docker
+  settings:
+    username:
+      from_secret: gitea_user
+    password:
+      from_secret: gitea_password
+    registry: $REGISTRY_URL/97waterpolo
+    repo: $REGISTRY_URL/97waterpolo/aoc-2021-2-0821
+    dockerfile: AOC2021/Dockerfile
+  environment:
+    REGISTRY_URL:
+      from_secret: gitea_registry_url    
+
 - name: build-aoc-2021
   image: plugins/docker
   settings: