Support for new fediverse:creator tag

[juanro49]

Mastodon 4.3 introduced a new meta tag that you can add to the HTML of your website, so publishers can feature the fediverse profile of the page author in the link previews on Mastodon. This post shows how it works.

<meta name="fediverse:creator" content="@[email protected]" />

I think it would be a good idea to add it to Plume, so that the plume user who wrote the article appears in the link preview.

mastodon/mastodon#30398