Yes, and this may be a much smaller effort than you suspect. Only by writing the output of --help in a certain order, you can use the "help2man" tool to generate a beautiful manpage automatically. Notice that your users do not need to have help2man installed, you run it yourself as part of your build process, to create the manpage from the latest source code.

It is very likely that if your tool already has a --help option, you don't really need to do anything to have a manpage. Just call help2man from your makefile.