feat: 2021 day 1

Author: Programator2

Diff for: 2020/aoc.py

@@ -6,15 +6,15 @@ def lines(path):
         return f.readlines()
 
 
-def file(path):
+def file(path: str) -> str:
     """
     Return contents of a file at `path` as a string
     """
     with open(path) as f:
         return f.read()
 
 
-def filerstrip(path):
+def filerstrip(path: str) -> str:
     """
     Return rstripped file contents of file at `path`
     """