ci: add drone configuration

.drone.yml

@@ -0,0 +1,39 @@
+---
+
+kind: pipeline
+type: docker
+name: default
+
+clone:
+  disable: yes
+
+steps:
+  - name: deploy staging
+    image: ghcr.io/appleboy/drone-ssh
+    environment:
+      INSTANCE: staging
+    settings: &settings
+      host:
+        from_secret: ssh_host
+      username:
+        from_secret: ssh_username
+      key:
+        from_secret: ssh_key
+      script:
+        - sudo deploy-shiftregister.sh "$$INSTANCE"
+    when:
+      branch:
+        - main
+
+  - name: deploy production
+    image: ghcr.io/appleboy/drone-ssh
+    environment:
+      INSTANCE: production
+    settings: *settings
+    when:
+      branch:
+        - live
+
+trigger:
+  event:
+    - push