Which publishing platform would syndicate to Mastodon?

I have a site where I often update the content - sometimes adding a new page/entry, but more often updating an existing entry. Right now everything is done by hand: a text editor and an FTP client. After I update the site I often then go to Mastodon and hand-write a post talking about the update. But I wonder if there's a way to automate that with a publishing platform - for blogs, or wikis, or otherwise - that would post to Mastodon any time I updated or added a page, linking back to the updated page. I know that I would need to migrate my hand-built content to a platform of some sort - that's fine. I just wonder which platform it would be. And I would prefer something open-source and/or ethical, not a big corporate - certainly not a Big Tech-owned - platform.

I'm familiar with POSSE (Publish (on your) Own Site, Syndicate Elsewhere) but am not sure how to put it in practice in this case. Thanks in advance.