Notes on where I got the utf8 width info.

door/utilities.go

@@ -7,6 +7,7 @@ import (
 	"golang.org/x/text/width"
 )
 
+// https://siongui.github.io/2016/03/23/go-utf8-string-width/
 func UnicodeWidth(r rune) int {
 	p := width.LookupRune(r)
 	if p.Kind() == width.EastAsianWide {