public static void main(String[] args) {
        App app = new App();
        int exitCode = new CommandLine(app).execute(args);
        if (app.exit) {
            System.exit(exitCode);
        }
    }
Invokes {@link #generateManPage(Config, CommandLine.Model.CommandSpec...)} to
generate man pages for the user-specified {@code @Command}-annotated classes.
<p>
If the {@code --exit} option is specified, {@code System.exit} is invoked
afterwards with an exit code as follows:
</p>
<ul>
<li>0: Successful program execution.</li>
<li>1: A runtime exception occurred while generating man pages.</li>
<li>2: Usage error: user input for the command was incorrect, e.g., the wrong
number of arguments, a bad flag, a bad syntax in a parameter, etc.</li>
<li>4: A template file exists in the template directory. (Remove the
`--template-dir` option or use `--force` to overwrite.)</li>
</ul>





@param args command line arguments to be parsed. Must include the classes to
            generate man pages for.
docs/genadoc.java