added user choice to join or create group

helpers/validateUserChoice.js

@@ -0,0 +1,19 @@
+module.exports.validateUsersChoice = (choice, options) => {
+  if (!choice) {
+    return {
+      isValid: false,
+      message: "User Choice is mandatory",
+    };
+  }
+
+  if (!options.includes(choice)) {
+    return {
+      isValid: false,
+      message: `Invalid choice, Please choose one of the options: ${options.join(
+        ", "
+      )}`,
+    };
+  }
+
+  return { isValid: true };
+};