add ruff linter and refactor all code

additional_functions.py

@@ -1,9 +1,11 @@
-import re
 import datetime
-from aiogram.types import Message, ReplyKeyboardMarkup, KeyboardButton
+import re
+
 from aiogram import Bot
-from get import get_timetable_for_day, fetch_timetable_data
+from aiogram.types import KeyboardButton, Message, ReplyKeyboardMarkup
+
 from DB import UseDB
+from get import fetch_timetable_data, get_timetable_for_day
 
 
 def get_group_id(user_id):