Add missing import and fix typo

Author: somacdivad

ch17-graphical-user-interfaces/6-challenge.py

@@ -2,6 +2,7 @@
 # Solution to challenge
 
 import tkinter as tk
+from tkinter import filedialog
 import random
 
 
@@ -151,7 +152,7 @@ def make_poem():
 # function to save the poem displayed in the output box into a text file
 def save_file():
  type_list = [("Text files", "*.txt")]
- file_name = tk.filedialog.asksaveasfilename(
+ file_name = filedialog.asksaveasfilename(
  filetypes=type_list, defaultextension="*.txt"
  )
  print(file_name)