Added type annotations

Author: fxf8

src/main.py

@@ -3,8 +3,8 @@
 import sys
 import manual_docstr
 
-def main():
-    filenames = sys.argv[1:]
+def main() -> None.__class__:
+    filenames: list[str] = sys.argv[1:]
 
     if len(filenames) == 0:
         print(manual_docstr.__doc__)