For those who are like me and don't know the term, "a language server for HTML" is referring to the plugin that evaluates your HTML syntax. That might be a narrow explanation of the tool but that's the basic idea I got from trying it.
<!DOCTYPE html>
<html>
<!-- content goes here -->
</html>> An html element's start tag can be omitted if the first thing inside the html element is not a comment.
> An html element's end tag can be omitted if the html element is not immediately followed by a comment.
The only explicit tag that is required for every HTML document is <title>, which you supposed boilerplate misses.
> The start tag may be omitted if the first thing inside the <html> element is not a comment.
> The end tag may be omitted if the <html> element is not immediately followed by a comment.
1: https://developer.mozilla.org/en-US/docs/Web/HTML/Element/ht...
I've tried omitting those tags, but I decided that in the end things are easier to read when you do include them, so nowadays I always include them when I write HTML.
> This language server is stricter than the HTML spec whenever it would prevent potential human errors from being reported.
If your goal is to output minimal HTML, let a tool automate that. Forgetting to open <html> is more likely a mistake than shorthand, and as shorthand it's not valuable.