Images are corrupted during local testing

## steps

1. Set up a local g8 test project.
2. Include an image.
3. Run the local test process to generate a project from your template.
4. Try and view the image.

When trying to view the image: I couldn't preview it in VSCode and it wouldn't load in a browser.

sbt or Giter8 version: `0.16.2`

## problem

My initial guess was that the file was being treated as a text file and pushed through the templating engine, however, [this ancient issue](https://github.com/foundweekends/giter8/issues/13) suggests that shouldn't be the case.

My second guess is that the transfer process is somehow mangling the data, but I haven't looked at what's really going on there so it is just a guess.

## expectation

I think that binary files should be correctly recognised and transferred 'as-is'.

## notes

This is my g8 template: https://github.com/PurpleKingdomGames/indigo.g8

This is the image I was trying to include:


This is the location I was putting it in:
https://github.com/PurpleKingdomGames/indigo.g8/tree/main/src/main/g8/assets