Fix: add type hints and doctests for Climbing Stairs

Author: noorinrahila

dynamic_programming/climbing_stairs.py

@@ -1,26 +1 @@
-"""
-Climbing Stairs Problem
-LeetCode #70
-Author: Noorin Rahila
-"""
-
-class Solution:
-    def climbStairs(self, n: int) -> int:
-        a = 1
-        b = 1
-        if n == 0:
-            return 0
-        elif n == 1:
-            return 1
-        else:
-            for i in range(1, n):
-                c = a + b
-                a = b
-                b = c
-            return b
-
-# Example usage
-if __name__ == "__main__":
-    s = Solution()
-    print(s.climbStairs(5))  # Output: 8