Punter (C1) protocol support

It's been requested to support sending (or receiving?) files to Commodore computers using the Punter (or more specifically, the "C1" protocol).

This could likely be implemented strictly in JavaScript. For reference: https://en-academic.com/dic.nsf/enwiki/815716#C1 https://github.com/mjgardner/cgterm/blob/master/punter.c

Requested on Facebook from Raymond A. Sirois Sr. "C1/New Punter would be nice, Multi-Punter would rock"