I'm wondering whether there is a place on AskDifferent to post helpful links for Apple-releated topics (e.g. I stumpled across https://hey-siri.io/ recently which lists possibly everything Siri can do for you). Is there a way to post these without breaking the rules?
Not really as this is out of scope for really any Stack Exchange site.
SE basic aim is to have the information on this site as from experience we have seen many links change and the information is lost.
In fact I think on many sites a reason to close a questions is if it asks for off site information which really is the only question your information could be provided as an answer to.
Also on one of the review queues an option is to delete a question for being link only.