feat: allow to set the height of the item

The user might want to show more than 2 lines, and, right now, if they
try to do so, things break.

Signed-off-by: Carlos A Becker <caarlos0@users.noreply.github.com>

list/defaultitem.go

@@ -86,6 +86,7 @@ type DefaultDelegate struct {
 	UpdateFunc      func(tea.Msg, *Model) tea.Cmd
 	ShortHelpFunc   func() []key.Binding
 	FullHelpFunc    func() [][]key.Binding
+	height          int
 	spacing         int
 }
 
@@ -94,14 +95,22 @@ func NewDefaultDelegate() DefaultDelegate {
 	return DefaultDelegate{
 		ShowDescription: true,
 		Styles:          NewDefaultItemStyles(),
+		height:          2,
 		spacing:         1,
 	}
 }
 
+// SetHeight sets delegate's preferred height.
+func (d *DefaultDelegate) SetHeight(i int) {
+	d.height = i
+}
+
 // Height returns the delegate's preferred height.
+// This has effect only if ShowDescription is true,
+// otherwise height is always 1.
 func (d DefaultDelegate) Height() int {
 	if d.ShowDescription {
-		return 2 //nolint:gomnd
+		return d.height
 	}
 	return 1
 }