refactor(weather): add app_build method

gismeteo/datehelp.py

@@ -1,9 +1,18 @@
 import datetime
+from enum import Enum
 
 import dateparser
 import dateparser.date_parser
 
 
+class Day(str, Enum):
+    TODAY = "today"
+    TOMORROW = "tomorrow"
+    DAY_3 = "3-day"
+    DAY_4 = "4-day"
+    DAY_5 = "5-day"
+
+
 def parse(value: str) -> datetime.date:
     if value == "today" or value == "mock":
         return datetime.date.today()