I have recently started using Fsnotes [1]. Its based on nvAlt [2]. If we are focusing on networked notes, fsnotes supports it out of the box and best part, it is offline; stores files as markdown on my local machine, which I really want. Not sure if Roam or Athens are offline apps, didn't dig too much into them.
There are two use-cases: project pages (from github repo README) and blog-posts (coming from .md files in blog-posts repo). You can choose to not have blog-posts and it will still generate a blog-like site from all your github project READMEs.