Indicate when a post is part of a larger conversation

[WovenTales]

Describe

If a post in the feed is a reply to some other one, display some indicator. Similarly, if there are other posts replying to it, display some other indicator (perhaps a "number of replies" counter similar to the boost/favorite counters). If it matters, this is assuming Mastodon's interaction model.

Why

With the current state of the interface, in order to see if anyone has responded to a post, you have to open it in the sidebar (using the not-quite-intuitive action of clicking the timestamp, but that's a separate issue). In the other direction, you can often get a feeling for whether some post is in reply to another one through the @-tags and the working used, but even there you have to open it in the sidebar to be sure. This flow might be better with the keyboard shortcuts, but it's still a bit onerous and in the majority of cases I'm lazy and just read the feed itself rather than the full (and just as valuable if not more so) conversation.

In the case of replies to a post, the counts next to the favorite and boost icons already provide a concise and consistent indicator, and I'd suggest the same next to the reply icon; the question there is which posts should be counted up for that number -- I'd personally lean toward just the direct replies a single level below, but I don't know what the Fediverse APIs provide easy access to. Marking that the post is itself a reply to something is less obvious, but I'd probably use a similar marker as the current "boosted by" line; however, simply replacing the boost icon with the reply icon is likely too subtle, and nothing else comes to mind immediately.