[Feature Request] Sort posts list by newest comment

[pintassilgo]

In addition to best/hot/new/top/rising, I suggest adding something like "recent activity" to sort posts list by most recent comment.

On reddit, if you append /comments to subreddit main page, you see latest comments from current subreddit/multireddit (example: https://www.reddit.com/r/news/comments/), but it's almost useless to see these comments without any context. But this shows a hint that it's possible to retrieve which are the most recent comments from the entire subreddit/mulltireddit.

I think it would be useful to list posts by latest comment, similar to threads list in forums/discussion boards.