input: Write a function to create a simple Tkinter window with a greeting label.
  assert create_greeting_window() is not None
output: import tkinter as tk
  
  def create_greeting_window():
      root = tk.Tk()
      root.title("Greeting Window")
  
      label = tk.Label(root, text="Hello, welcome to the Tkinter window!")
      label.pack()
  
      root.mainloop()
  
      return root