fix old skins broken by MediaWiki heading HTML changes

[NovemLinguae]

fixes #44

[NovemLinguae]

Note to self: the XFDCloser documentation says that it also supports Modern and Timeless, but I think those are also broken. Maybe I should try to patch those here as well.

Root cause is probably https://www.mediawiki.org/wiki/Heading_HTML_changes

[evad37]

Hi, thanks for your interest in contributing/maintaining code, I don't really have time to these days. Please go ahead with any changes you want to make, the deployment steps in https://github.com/wikimedia-gadgets/xfdcloser?tab=readme-ov-file#deployment and https://github.com/wikimedia-gadgets/xfdcloser/blob/master/bin/deploy.js should be fairly self-explanatory

[NovemLinguae]

@evad37 Sounds good. Thanks for the reply and for making the tool. I've got enough access (wikimedia-gadgets member, interface admin) to do some maintenance on it, and it sounds like you're OK with it, so I'll go ahead and see what I can do. Be well my friend :)