Bring problem_29 solution in line with project style guidelines (TheAlgorithms#2949)

Author: nthall

Diff for: project_euler/problem_29/solution.py renamed to project_euler/problem_29/sol1.py

@@ -16,7 +16,7 @@
 """
 
 
-def solution(n):
+def solution(n: int = 100) -> int:
     """Returns the number of distinct terms in the sequence generated by a^b
     for 2 <= a <= 100 and 2 <= b <= 100.