xt-build generates incompatible output (us-ascii character set instead of utf-8)

[aendra-rininsland]

Describe the bug
Some part of the code generation side of this tool converts the character set from UTF-8 to us-ascii, resulting in errors like the following:

Running file -I dist/content.js returns:

dist/content.js: text/plain; charset=us-ascii

This has effectively stopped me in my tracks and ended my use of this tool — I'm not remotely pleased at having to re-scaffold my project right now.

To Reproduce
Steps to reproduce the behavior:

1. Scaffold
2. npm start
3. Load unpacked extension in Chrome; navigate to dist/
4. See error

Expected behavior
The in-dev extension loaded in Chrome

Desktop (please complete the following information):

• OS: MacOS 12.6
• Browser Chrome
• Version 106.0.5249.119
• Node.js 16.13.2