Copyright for vtgamma source package in Sid

Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
Upstream-Name: vtgamma
Source: https://github.com/kilobyte/vtgamma

Files: *
Copyright: 1999-2017 Adam Borowski 
License: PD
 I hereby disclaim all copyright on this software and the packaging, and
 put it in the Public Domain.  If this is impossible in a given jurisdiction,
 an all-permissive license is granted.