Added sample for custom actions

sample/script-sample.js

@@ -0,0 +1,10 @@
+
+const arguments = process.argv;
+
+if (arguments && arguments.length > 0) {
+  const workspaceArg = arguments[2]; // The workspace path
+  const fileArg = arguments[3]; // The file path
+  const frontMatterArg = arguments[4]; // Front matter data
+
+  console.log(`The content returned for your notification.`);
+}