Issue on submission-digitalpublicgoods

[nathanfletcher]

## What were you trying to do
Upload static .html file with a few graphics to a subpath on my site, then access them as "path/to/root/"

## Expected Behavior
From the `index.html` root, images also residing at that root should be available by relative path when accessing "path/to/root/" OR "path/to/root/index.html"

## Current Behavior
When accessing just "path/to/root/" the images (relative reference in CSS files) are trying to resolve from the parent directory "path/to/"

## Environment used
Google Chrome

## Steps to Reproduce
You can see this here https://benjaminwfox.com/lab/js13k/2023/khan/index.html (working) vs here https://benjaminwfox.com/lab/js13k/2023/khan/ (no images) - you can inspect the elements html -> body -> div#board and see an example, b.png, and the path the browser is expecting.

Created on: _2023-09-08T14:44:42.310Z_