We use '+++' syntax to output a literal '**' for a '--glob' example.
This '+++' syntax is pretty ugly when rendered literally via --help. We
fix this by hackily inserting the '+++' syntax for its one specific case
that we need it during man page generation.
Not ideal but it works. And --help still has some '*foo*' markup, but we
live with that for now.
Fixes#1581