Will edit it in when I find more but this is Lemmy’s markdown tutorial. It covers a few items uniqueish to lemmy, especially cool are magnet links, but I’m not sure where they keep info about other unique features. Offhandedly, the only other thing I can think of is linking to profiles with @Gullible. (This does ping the user, btw)
Edit: I got nothing, it’s impossible to find and/or doesn’t exist. No other option. But if someone else finds it, a link would be helpful.