update html_imports for explanation of html module

[songhn233]

Added an explanation of the html module, reference to WICG/webcomponents, whatwg/html#4505.

[github-actions]

Preview URLs

• https://pr9235.content.dev.mdn.mozit.cloud/en-US/docs/Web/Web_Components/HTML_Imports

Flaws

None! 🎉

External URLs

URL: /en-US/docs/Web/Web_Components/HTML_Imports
Title: HTML Imports
on GitHub

• https://github.com/WICG/webcomponents/blob/gh-pages/proposals/html-modules-explainer.md (1 time) (Note! This may be a new URL 👀)
• [WIP] Introduce HTML Modules whatwg/html#4505 (1 time) (Note! This may be a new URL 👀)

[ddbeck]

Hi @songhn233 and thanks for this PR. I see it's your first to the project—welcome!

Typically, we try to avoid documenting very new or unstable web features, particular features that exist only as proposals with little or no consensus. You've discovered an interesting case where we've continued to cover a feature that's no longer useful to web developers (in a poorly-linked part of MDN, luckily).

I'd welcome coverage of these alternatives, when they've progressed to the prototyping stage in working browsers. Until then, I think we should avoid bringing them up, until they're of practical use to web developers generally.

I'll open a new PR that deals with this content in another way. Thank you for bringing this to our attention.