Display tagged content from other users in the feed.

[rabble]

In patchwork and some other ssb apps you can tag somebody messages. These can be your own or somebody else's. This is a great way to curate content, give it context, and in effect share.

First off we could have a display card in the feed which displays tagged content. Either something like how we have the follow message... "Rabble has tagged Bob's post with: Interesting" and then some summary of the post. You can tap on 'interesting' to see what else has been tagged interesting (we'd probably want to combine hashtags and tags in that view). Or you can see the content of the message.

What this gives us is BOTH curation and sharing of posts. This ticket is not for making it so users can create tags, that's a separate ticket. Creating tags requires a bit more UI work. We have tagged content already, let's expose that to users.

@Chardot has a design for a instagram stories type model for this sharing, which is also worth investigating. The first way of a card in the feed feels faster.