check supported number of colors

[github-actions]

TODO: color schemes? (8-col, original cbonsai, monochrome)

---

gobonsai/colors.go

Lines 18 to 23 in af75dcb

	// TODO: check supported number of colors
	// TODO: color schemes? (8-col, original cbonsai, monochrome)
	// based on type of tree, determine what color a branch should be
	func chooseColor(kind branch) tcell.Style {
	switch kind {

---

This issue was generated by todo-issue based on a TODO comment in af75dcb.