Enhancement: Better thread display

[zergling-man]

It's difficult to tell which posts are replying to which in conversations; even relatively short ones. Would be nice if there was a way to display posts as thread chains, eg. https://linuxrocks.online/system/media_attachments/files/105/699/749/563/295/807/original/375a199b4bdd07f1.png

I would certainly prefer this over the current "details" popup, so I'm ok with it being an alternative to that; I don't use anything in there other than "context before" and "context after". (And "this toot" for cross-account stuff.)