Write group_by_letter(words) returning a dict mapping each first letter (lower case) to the list of words starting with it, in original order.
group_by_letter(['apple', 'Avocado', 'banana'])
→ {'a': ['apple', 'Avocado'], 'b': ['banana']}group_by_letter([])
→ {}Submit runs 3 tests, including hidden edge cases.
Run your code to see the output here.