I agree that https://rpg.stackexchange.com/q/77169/23970 isn't a great question for the site. One step worse than a "read the book to me," it's a "read the ToC to me" question. However...
Would What are the official (WotC) playable races in 5e? be an acceptable question for the site? The obvious answer would be a listing table listing races and sources. Perhaps a community wiki? (What else are community wikis good for, anyway?)
Now I know we shy away from list questions. But the problem with list questions isn't the enumeration of the list, it's the lack of discrimination among list elements, when submitted as single answers (2). If the questions starts as CW, does that circumvent the problem?
Well, here's the question and answer. Enjoy.
It was Community Wiki for a while, but after months of getting comment-pings asking "should this be included" and "how's this edit look" I went ahead and reclaimed authorship. That doesn't seem to have done anything to dissuade good edits from the community.