Restarted the production of the app

libs/CLI11/examples/subcom_help.cpp

@@ -0,0 +1,21 @@
+// Copyright (c) 2017-2022, University of Cincinnati, developed by Henry Schreiner
+// under NSF AWARD 1414736 and by the respective contributors.
+// All rights reserved.
+//
+// SPDX-License-Identifier: BSD-3-Clause
+
+#include <CLI/CLI.hpp>
+#include <iostream>
+#include <string>
+
+int main(int argc, char *argv[]) {
+    CLI::App cli_global{"Demo app"};
+    auto &cli_sub = *cli_global.add_subcommand("sub", "Some subcommand");
+    std::string sub_arg;
+    cli_sub.add_option("sub_arg", sub_arg, "Argument for subcommand")->required();
+    CLI11_PARSE(cli_global, argc, argv);
+    if(cli_sub) {
+        std::cout << "Got: " << sub_arg << std::endl;
+    }
+    return 0;
+}