Thanks to @Suvrutt_Gurjar and @Joseph_Seddik for your very informative responses.
In regard to GAS, I asked a couple of questions about templates using GAS here:
If someone makes a template / sample app that utilizes Google Apps Script, will the script be copied when the template is copied? Or, will it need to be added manually to the template / sample app after it has been copied? Also, is there a template / sample app that utilizes Google Apps Script? If there is such an app and if all I have to do is copy it and then start “looking under the hood” that’s what I’d like to do.
A sample app would really help me understand what GAS can do.