Add support for fediverse:creator

I've tried to do the initial integration, mainly looking at other tags how they were done.
If I install the OpenGraph submodule I got the new field. But not sure if anything special needs to be done to update existing installations and if there is need for extra test for new field.

Thank you for putting that together.

Please create the merge request from your issue fork and we can see how it works in the tests.

Merge request created. It took a bit of trial and error (and help from Daniel Pickering) to find how to do that. :)

Okay, let’s give this a test!

I’ve rolled the test out to https://rachelnorfolk.me and it does appear in the list of meta tags in head.

Exporting meta tag configuration does appear to work correctly.

Articles posted on a correctly configured account do appear to give attribution correctly. See https://norfolk.social/@rachel/113640387689376743

Looks great to me!!