Document -RefreshIG and other command line options

[p9g]

Is your feature request related to a problem? Please describe. The Main.java does not have complete documentation of the various command line options, such as -RefreshIG.

Describe the solution you'd like Add a comment in Main.java which mentions that additional command options may be defined in OperationFactory

Describe alternatives you've considered Complete documentation in Main.java, or a separate markdown document or wiki page to fully describe each command line option.