AFAIK, Medium does support embedded Gists from GitHub etc. At least it did when I last wrote a programming guide in it.
Update: Still seems that it does (scroll down) [0]
Edit: Oops, I just remembered that HackerNoon moved off Medium to their own CMS, but those Gists did used to work on Medium too, complete with code formatting.
[0] - https://hackernoon.com/building-a-face-recognition-web-app-i...