input: Write a function to implement a sorting algorithm in Python that takes a list of integers as input and outputs the list sorted in ascending order. The function should return the sorted list.
  assert sort_ascending([64, 34, 25, 12, 22, 11, 90])==[11, 12, 22, 25, 34, 64, 90]
  assert sort_ascending([5, 3, 8, 6, 7, 2])==[2, 3, 5, 6, 7, 8]
  assert sort_ascending([])==[]
  assert sort_ascending([1, 2, 3, 4, 5])==[1, 2, 3, 4, 5]
  assert sort_ascending([9, 8, 7, 6, 5, 4, 3, 2, 1])==[1, 2, 3, 4, 5, 6, 7, 8, 9]
output: def sort_ascending(lst):
      return sorted(lst)