Feature summary (what you would like to be able to do and where):
As administrator of the mailing list for the Wikibase Community User Group, I want to be able to add the rel="me" attribute to a link on the list's info page so that the reciprocal link to the mailing list on the group's Wikis.world Mastodon profile shows as verified.
Use case(s) (list the steps that you performed to discover that problem, and describe the actual underlying problem which you want to solve. Do not describe only a solution):
When editing the group's user profile on Wikis.world, I noticed that the links within it were not showing up in green, like some other profiles. Upon consulting the documentation, I found that this would be triggered by adding a reciprocal link with the rel="me" attribute (or, an equivalent <link> in <head>).
I duly did so by editing the mailing list's settings, only to find that on display the text:
<a rel="me" href="https://wikis.world/@WikibaseCommunity">Mastodon</a>
was being turned into:
<a href="https://wikis.world/@WikibaseCommunity" rel="nofollow">Mastodon</a>
The relevant profile link on Wikis.world therefore do not show up as verified.
Benefits (why should this be implemented?):
Allowing such attributes and thus enabling validation would increase the confidence in the link and attract Mastodon users to review the mailing list, which has group content that in many cases is not posted to other areas.
(This has been done for Wikimedia user pages in T322717, though the group can't do it that way because its Meta page isn't in the User: namespace - it looks like T324937 applies and we can request an edit to MediaWiki:Realme-config.json on Meta instead.)