This is really neat, and close to something I have always wanted to implement for managing a small local notes handling system.
(As a side note which may be a kind of artifact of coding turf wars, I just can't consider a Node application with a number of dependencies truly lightweight, no matter how straightforward in practice. I know this is more lightweight than most comparably scoped applications, and the term lightweight often just implies fast / efficient / easy, but the overhead required for a standard Node JS setup appears contrary to the concept of lightweight in principal. Have at me).
So basically blot.im?
I was looking to host my Markdown files (an Obsidian vault) as easy as possible without the need to run Jekyll, Hugo and so on.
Besides https://otterwiki.com/, Renato seems to be a suitable option.