misc: add GitHub actions for automatic deployment

.github/main.workflow

@@ -0,0 +1,13 @@
+workflow "New workflow" {
+  on = "push"
+  resolves = ["Deploy"]
+}
+
+action "Deploy" {
+  uses = "actions/npm@59b64a598378f31e49cb76f27d6f3312b582f680"
+  env = {
+    GIT_USER = "yangshun"
+    USE_SSH = "1"
+  }
+  runs = "deploy"
+}