This is an example project intended entirely for personal use while I play around with Enhance.
The official Enhance docs recommend using es6-string-html and literally-html for syntax highlighting and formatting. I've found that the latter doesn't work on Windows, so, after scouring the internet for a solution, I found this discussion for on the Lit repository with recommends using Prettier via ESLint with a the Lit plugin.
The only thing that wasn't working was formatting on save. This worked for everything outside the template literals, but not for the HTML inside. Since the ESLint/Prettier fixes were still working when I triggered them manually, I added the following to my VS Code settings to trigger them on save:
"editor.codeActionsOnSave": {
"source.fixAll.eslint": true
}