This Kitty terminal isn't new. Going by the history on GitHub, this terminal predates the one you linked by a couple years.
First commit of Kovid Goyal kitty in October 2016:
* https://github.com/kovidgoyal/kitty/tree/de072b3b423ad114cc4...
Hacker News post about the KiTTY fork of PuTTY in September 2011:
* https://news.ycombinator.com/item?id=2979382
And that's not the earliest for the latter.
SO question from 2012 asking about KiTTY: https://superuser.com/questions/410398/any-simple-way-to-add...