This means that any HTML file inside /content will be treated as a regular file.
If you want it processes with shortcodes and a layout, add front matter.
The defintion of an HTML file here is:
* File with extension .htm or .html
* With first non-whitespace character "<" that isn't a HTML comment.
This is in line with the documentation.
Fixes #7030
Fixes #7028
See #6789