Hey Tobbe, thanks for moving to Hashnode, and writing this piece. Just a quick clarification, we do show instructions right after you map a domain.

The green ticks denote if your domain is configured properly, and ready. We have our support docs, but I don't think we currently link to it from the domain tab. We'll consider adding it.
Nice! Congrats and welcome to Hashnode!
Tony Xu
Software Engineer @linkedin
I have same problem, I want to map my existing blog URLs to hashnode posts.