Recommend new sources to follow in main feed#94

Similar to how Scour recommends new topics while you’re scrolling your feed, it would be nice if it also showed you new sources to follow.

It would be useful if it would also show you one or maybe multiple articles from that source related to your interests that would help you decide if you wanted to add it.

(Thanks @tiferrei for the suggestion!)

If you are subscribed to specific feeds (as opposed to always scouring all feeds), feed recommendations will show up as you’re scrolling through your personal feed.