input: Write a function to take in two strings and return a list of all the words in both strings. The given strings should be split into individual words and then concatenated into a single list. The function should be named string_to_list and it should accept two parameters, s1 and s2. The output should be a list of words from both input strings.
  
  assert string_to_list("I want to make a difference", "The journey to success is long")==['I', 'want', 'to', 'make', 'a', 'difference', 'The', 'journey', 'to', 'success', 'is', 'long']
  assert string_to_list("Hello world", "Goodbye world")==['Hello', 'world', 'Goodbye', 'world']
  assert string_to_list("", "")==[]
  assert string_to_list("One string", "")==['One', 'string']
  assert string_to_list("", "Another string")==['Another', 'string']
output: def string_to_list(s1, s2):
      return s1.split() + s2.split()