新增不指定参数执行程序显示帮助信息“

src/jfhdconvertor/main.cpp

@@ -130,7 +130,7 @@ cxxopts::ParseResult parse(int argc, char* argv[])
 
 	auto result = options.parse(argc, argv);
 
-    if (result.count("help"))
+	if (0 == result.arguments().size() || result.count("help"))
     {
 		std::cout << options.help({ "" , "pcd2las.auto", "pcd2las" }) << std::endl;
 		exit(0);