Copyright for numix-gtk-theme source package in Focal

Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
Upstream-Name: numix-gtk-theme
Source: https://github.com/numixproject/numix-gtk-theme

Files: *
Copyright: Copyright 2013 Satyajit Sahoo 
License: GPL-3+
 This program is free software; you can redistribute it
 and/or modify it under the terms of the GNU General Public
 License as published by the Free Software Foundation; either
 version 3 of the License, or (at your option) any later
 version.
 .
 This program is distributed in the hope that it will be
 useful, but WITHOUT ANY WARRANTY; without even the implied
 warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 PURPOSE.  See the GNU General Public License for more
 details.
 .
 You should have received a copy of the GNU General Public
 License along with this package. If not, see
 .
 .
 On Debian systems, the full text of the GNU General Public
 License version 3 can be found in the file
 `/usr/share/common-licenses/GPL-3'.