provide examples for maven plugin parameters

The maven plugin has a help goal (antlr4:help -Ddetail=true), but the resulting list should give the syntax for the parameters when used in a pom.xml file. For example, the antlr4:antlr4 goal describes "arguments" as "A list of additional command line arguments to pass to the ANTLR tool." Would be handy if this description showed the syntax to use for the "list".

This would not necessarily have to be in the maven goal's output (though that would be nice), but at least the website could give details.

Information needed:
- XML hierarchy for the parameters.
- Syntax for the parameters: tag names, tag values, etc.
- Some parameters are on/off, others have values. Need details for both.
- Some parameters are default on, others default off. Details on how to reverse a value.

I have looked through the maven documentation, but nothing I have tried yet works.
I have turned on maven debugging, but that has not yet shown enough to help.

Start by running the documented antlr4:help -Ddetail=true goal and inspecting the antlr4:antlr4 goal's parameter descriptions, especially arguments. Compare the output with the Maven plugin documentation on the website; done means documenting each parameter's XML hierarchy, tag syntax, values, defaults, and how to reverse boolean settings.

Written by the indexing model from the issue text.