Add GH actions workflow

.github/main.workflow

@@ -0,0 +1,9 @@
+workflow "Build and deploy on push" {
+  resolves = ["Docker Registry"]
+  on = "push"
+}
+
+action "Docker Registry" {
+  uses = "actions/docker/login@8cdf801b322af5f369e00d85e9cf3a7122f49108"
+  secrets = ["DOCKER_USERNAME", "DOCKER_PASSWORD"]
+}