improve docstrings in insertion_sort.py to include complexity analysis

Author: dhruv-gautam-dev

sorts/insertion_sort.py

@@ -30,6 +30,10 @@ def insertion_sort[T: Comparable](collection: MutableSequence[T]) -> MutableSequ
     :param collection: some mutable ordered collection with heterogeneous
     comparable items inside
     :return: the same collection ordered by ascending
+    
+    Time Complexity: O(n^2) - worst and average case
+    Time Complexity: O(n) - best case (already sorted, inner while never runs)
+    Space Complexity: O(1) - sorts in place, no extra memory used
 
     Examples:
     >>> insertion_sort([0, 5, 3, 2, 2])