https://github.com/merefield/termcourse/pull/2
So the rendering wasn’t great … so I’ve fixed it … the UI now has “diff rendering” so it’s much faster and smoother … it no longer paints the whole screen with every cursor movement. 
I’ve only tested this under windows so far so please feed back any issues - but it should help slower systems significantly.
I’ve also added some tests and GitHub CI! (and it’s super fast because it uses minitest)