Goldmark's extension.footnote Abbrevations support

Hi, I see that Goldmark in the built-in extension.Footnote, that is active or I would have no footnotes, also includes abbrevations, but the following won’t work:

*[HTML]: Hyper Text Markup Language
essai HTML sdfsd

I don’t see any issue raised in the github page, nor here (not recent ones related to the Goldmark era !) so I don’t know if there’s an option to pass and I don’t understand how/which, or if the feature just isn’t supported.