docs: added some examples to godoc

list/list_test.go

@@ -1,6 +1,7 @@
 package list_test
 
 import (
+	"fmt"
 	"strings"
 	"testing"
 
@@ -10,6 +11,24 @@ import (
 	"github.com/charmbracelet/lipgloss/tree"
 )
 
+// XXX: can't write multi-line examples if the underlying string uses
+// lipgloss.JoinVertical.
+
+func ExampleNew() {
+	list := list.New().
+		Item("First")
+	fmt.Print(list)
+	// Output:• First
+}
+
+func ExampleNew_customEnumerator() {
+	list := list.New().
+		Enumerator(list.Arabic).
+		Item("First")
+	fmt.Print(list)
+	// Output:1. First
+}
+
 func TestList(t *testing.T) {
 	l := list.New().
 		Item("Foo").

tree/tree_test.go

@@ -1,6 +1,7 @@
 package tree_test
 
 import (
+	"fmt"
 	"testing"
 
 	"github.com/charmbracelet/lipgloss"
@@ -10,6 +11,28 @@ import (
 	"github.com/charmbracelet/lipgloss/tree"
 )
 
+func ExampleNew() {
+	tree := tree.New().
+		Item("First")
+	fmt.Print(tree)
+	// Output: └── First
+}
+
+func ExampleNew_root() {
+	tree := tree.New().
+		Root("Root")
+	fmt.Print(tree)
+	// Output: Root
+}
+
+func ExampleNew_round() {
+	tree := tree.New().
+		Enumerator(tree.RoundedEnumerator).
+		Item("First")
+	fmt.Print(tree)
+	// Output: ╰── First
+}
+
 func TestTree(t *testing.T) {
 	tree := tree.New().
 		Items(