Provide more details with the -h option

[cacraigucar]

Currently the -h option for git-fleximod is pretty terse. The .lib/bin-gitfleximod/README.md has much more information including example usage, but it is hidden in the .lib directory and then a further level down. One suggestion for giving more information in the -h option is to populate it with the text which resides in the hidden README.md.