new port: textproc/rubygem-rugments

Simple, easy to extend drop in replacement for pygments

WWW: https://github.com/rumpelsepp/rugments

PR: 199931
Differential Revision: https://reviews.freebsd.org/D2500
Submitted by: Torsten Zuehlsdorff <ports@toco-domains.de>
Approved by: mat (mentor)