gregex: Highlight some argument names in the documentation
gregex: Highlight some argument names in the documentation

Signed-off-by: Philip Withnall <withnall@endlessm.com>

https://bugzilla.gnome.org/show_bug.cgi?id=748620

endlessm/glib,endlessm/glib,endlessm/glib,endlessm/glib,endlessm/glib