Copyright for libyaml-shell-perl source package in Focal

This package was debianized by Alexander Zangerl .
It was downloaded from http://search.cpan.org/~ingy/YAML-Shell-0.60/

Upstream Author: Ingy döt Net 

Copyright:

"Copyright (c) 2006, 2008. Ingy döt Net.

 Copyright (c) 2001, 2002. Brian Ingerson.

 This program is free software; you can redistribute it and/or modify it
 under the same terms as Perl itself."

Perl is distributed under your choice of the GNU General Public License or
the Artistic License.  On Debian GNU/Linux systems, the complete text of the
GNU General Public License can be found in `/usr/share/common-licenses/GPL'
and the Artistic Licence in `/usr/share/common-licenses/Artistic'.