Send errors and missed reminders to webhook

New environment variable that you need to use for this to work.

discord_reminder_bot/settings.py

@@ -9,7 +9,8 @@ load_dotenv(verbose=True)
 sqlite_location = os.getenv("SQLITE_LOCATION", default="/jobs.sqlite")
 config_timezone = os.getenv("TIMEZONE", default="UTC")
 bot_token = os.getenv("BOT_TOKEN", default="")
-log_level = os.getenv(key="LOG_LEVEL", default="INFO")
+log_level = os.getenv("LOG_LEVEL", default="INFO")
+webhook_url = os.getenv("WEBHOOK_URL", default="")
 
 if not bot_token:
     raise ValueError("Missing bot token")