Apply suggestions from code review

Co-authored-by: Christophe Nanteuil <35002064+christopheNan@users.noreply.github.com>

README.md

@@ -33,7 +33,7 @@ optional arguments:
   --exclude-reserved    select only files that aren't reserved
   --only-reserved       Will print out only reserved files
   --show-reservation-dates
-                        Will show reservation_dates
+                        show issue creation dates 
   --version             show program's version number and exit
 ```
 

potodo/_github.py

@@ -71,9 +71,9 @@ def get_reservation_list(repo_path: Path) -> Dict[str, Tuple[Any, Any]]:
         # Maybe find a better way for not using python 3.8 ?
         yes = re.search(r"\w*/\w*\.po", issue["title"])
         if yes:
-            datetime_object = datetime.strptime(
+            creation_date = datetime.strptime(
                 issue["created_at"].split("T")[0], "%Y-%m-%d"
             ).date()
-            reservations[yes.group()] = (issue["user"]["login"], datetime_object)
+            reservations[yes.group()] = (issue["user"]["login"], creation_date)
 
     return reservations

potodo/potodo.py

@@ -373,7 +373,7 @@ def main() -> None:
         "--show-reservation-dates",
         action="store_true",
         dest="show_reservation_dates",
-        help="Will show reservation_dates",
+        help="show issue creation dates",
     )
 
     parser.add_argument(