Serving Directory Index Files With CloudFront Functions

I recently migrated from hosting this site on Gitlab pages (still an excellent option, BTW) to hosting on AWS S3 via CloudFront. This solution isn’t cheaper, but I’ve been working on AWS concepts of late and thought this would be a good exercise - and I was right! :-) I expect to write more about what I learned in that exercise, but I wanted to start with the problem of directory index files, since this solution didn’t come up often in my search for solutions....