Include "baseline" alerts from MDN

[paschun]

Feature request

Include "baseline" alerts from MDN.
For CSS/HTML/JS/DOM docs

Summary

It's cool and useful and easy to know if a feature has cross-browser support.
Just include the alert box that's in the source docs, as opposed to forcing users to navigate away to caniuse or MDN to check for support.

Examples

https://developer.mozilla.org/en-US/docs/Web/API/AbortController/AbortController (baseline: widely available)
https://devdocs.io/dom/abortcontroller/abortcontroller (not there)
https://developer.mozilla.org/en-US/docs/Web/CSS/:has (baseline: newly available)

https://web.dev/explore/baseline/2023
https://github.com/web-platform-dx/web-features/blob/main/packages/web-features/README.md?plain=1#L21-L24

[paschun]

Just noticed one page that does have a Baseline tag at the top, however it says Baseline: Widely supported on devdocs, but Baseline: newly available on MDN.

https://developer.mozilla.org/en-US/docs/Web/CSS/@layer