input: Write a function to generate a list of the first 'n' Fibonacci numbers.
  assert generate_fibonacci_list(10) == [0, 1, 1, 2, 3, 5, 8, 13, 21, 34]
  assert generate_fibonacci_list(5) == [0, 1, 1, 2, 3]
  assert generate_fibonacci_list(1) == [0]
output: def generate_fibonacci_list(n):
      if n <= 0:
          return []
      fibonacci_list = [0, 1]
      while len(fibonacci_list) < n:
          fibonacci_list.append(fibonacci_list[-1] + fibonacci_list[-2])
      return fibonacci_list[:n]