Add new schedule invitation answer template (#5)

Author: marcoacierno

pythonit_toolkit/emails/templates.py

@@ -5,6 +5,7 @@ class EmailTemplate(str, Enum):
     RESET_PASSWORD = "reset-password"
     NEW_COMMENT_ON_SUBMISSION = "new-comment-on-submission"
     SUBMISSION_ACCEPTED = "submission-accepted"
+    NEW_SCHEDULE_INVITATION_ANSWER = "new-schedule-invitation-answer"
 
     def __str__(self) -> str:
         return str.__str__(self)