Update main.workflow

.github/main.workflow

@@ -0,0 +1,15 @@
+workflow "Docker Hub Description Workflow" {
+  on = "push"
+  resolves = ["Docker Hub Description"]
+}
+
+action "Filter master branch" {
+  uses = "actions/bin/filter@v1.0.0"
+  args = "branch master"
+}
+
+action "Docker Hub Description" {
+  needs = ["Filter master branch"]
+  uses = "./"
+  secrets = ["DOCKERHUB_USERNAME", "DOCKERHUB_PASSWORD", "DOCKERHUB_REPOSITORY"]
+}