notranslate
Proposal:
Instead of <html> could be <html lang="en" class="notranslate" translate="no">.
Also <title> could contain filename...
@andrzejQ Why do you propose english as language? The input language is basically unknown I would say. Especially if the input is just plain text. Otherwise if it is program code it is probably english. And why should the content be not translated/translatable (https://www.w3.org/International/questions/qa-translate-flag.en)?
I prepared a test page. Problem appears in a browser, such as Chrome, with the option to automatically translate into non-English.
https://andrzejq.github.io/Jekyll_app1htmlFile/test/2002/09/18/html_notranslate_test.html
lang="" is ok - may be empty