btree: add a way to visualize the tree

main.go

@@ -11,16 +11,28 @@ func main() {
 	// Example program
 	t := btree.NewBtree(3)
 	t.Insert("animal", "dog")
+
+	s, _ := t.Search("animal")
+	fmt.Println(s)
+
 	t.Insert("potato", "fries")
 	t.Insert("6", "number")
 	t.Insert("12", "number")
 	t.Insert("car", "ferrari")
 	t.Insert("7", "number")
 	t.Insert("plane", "airbus")
+	t.Insert("animal", "cat")
+
+	s, _ = t.Search("animal")
+	fmt.Println(s)
 
 	fmt.Print("Traversal of the constructed tree is")
 	t.Traverse()
 
+	fmt.Println("")
+
+	t.Visualize()
+
 	if val, err := t.Search("6"); err != nil {
 		fmt.Print("\nNot Present")
 	} else {
@@ -32,4 +44,5 @@ func main() {
 	} else {
 		fmt.Printf("\nPresent: value '%s'", val)
 	}
+
 }