Feature description
Add a script property that if it exists, then the script take it's contents and adds them as a prefix to the subject title. In my case still using this for my doctors appointments case, it'd be nice to be able to tell the difference between the twelve day email(for scheduling ride to doctors, I'd leave it blank here, it'd look like usual) and the reminder that I have an appointment the next day(I'd fill it in with what ever text I want to differentiate it from the 12 day notice) .

**Feature description**
I'm disabled. I have to use the local free disability transporter. They only do scheduling for events happening no more than 12 days from when you schedule. I need a reminder that an event is twelve days from now and have it sent to my email so I see it when I check my email. For instance I had an appointment on Tuesday, May 24th. But I have to make the appointment with the transporter no less than 48 hours(business days) in advance. I forgot to call Friday. So I ended up having to reschedule the appointment. It would be nice if all events 12 days in advance from my Doctors calendar got sent in case there is more than one event on a certain date.

This issue was automatically created by Allstar.

Security Policy Violation
No protection found for branch main

This issue will auto resolve when the policy is in compliance.

Issue created by Allstar. See https://github.com/ossf/allstar/ for more information. For questions specific to the repository, please contact the owner or maintainer.

This issue was automatically created by Allstar.

Security Policy Violation
Security policy not enabled.
A SECURITY.md file can give users information about what constitutes a vulnerability and how to report one securely so that information about a bug is not publicly visible. Examples of secure reporting methods include using an issue tracker with private issue support, or encrypted email with a published key.

To fix this, add a SECURITY.md file that explains how to handle vulnerabilities found in your repository. Go to https://github.com/thomasleplus/google-apps-scripts/security/policy to enable.

For more information, see https://docs.github.com/en/code-security/getting-started/adding-a-security-policy-to-your-repository.

This issue will auto resolve when the policy is in compliance.

Issue created by Allstar. See https://github.com/ossf/allstar/ for more information. For questions specific to the repository, please contact the owner or maintainer.