Update colorschemes and add new ones

This commit updates the colorschemes and adds some new ones:

* gotham (https://github.com/novln/micro-gotham-colors)
* monokai-dark (https://github.com/Theodus/micro-monokai-dark)
* one-dark (https://github.com/joseluisq/micro-one-dark)
* sunny-day (https://github.com/dwwmmn/micro-sunny-day)

internal/display/bufwindow.go

@@ -417,6 +417,10 @@ func (w *BufWindow) displayBuffer() {
 	curNumStyle := config.DefStyle
 	if style, ok := config.Colorscheme["current-line-number"]; ok {
 		curNumStyle = style
+		if !b.Settings["cursorline"].(bool) {
+			_, bg, _ := lineNumStyle.Decompose()
+			curNumStyle = curNumStyle.Background(bg)
+		}
 	}
 
 	// We need to know the string length of the largest line number