Feature request: annotate at:// content #13

I don't know how this would work exactly, but I've been enjoying using margin.at while on bsky.app.

But it strikes me as un-ideal that I am making margin.at annotations directly on bsky.app. Ideally these annotations wouldn't necessarily have to be against the bluesky app (should it ever perhaps disappear, let's say), but could be against the content people share on bluesky. I'd like to be able to annotate people's PDS records more directly.

And to make this ask really complicated, I'd still somehow like those annotations to show up on bsky.app!

There's some related ideas here, about decoupling the protocol from particular instances/implementations: https://connectedplaces.online/reports/fr156-share-where/